Initial commit of vpp code.

Change-Id: Ib246f1fbfce93274020ee93ce461e3d8bd8b9f17
Signed-off-by: Ed Warnicke <eaw@cisco.com>
diff --git a/vnet/vnet/interface_output.c b/vnet/vnet/interface_output.c
new file mode 100644
index 0000000..84dc039
--- /dev/null
+++ b/vnet/vnet/interface_output.c
@@ -0,0 +1,1311 @@
+/*
+ * Copyright (c) 2015 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.
+ */
+/*
+ * interface_output.c: interface output node
+ *
+ * Copyright (c) 2008 Eliot Dresselhaus
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <vnet/vnet.h>
+
+typedef struct {
+  u32 sw_if_index;
+  u8 data[64 - sizeof (u32)];
+} interface_output_trace_t;
+
+u8 * format_vnet_interface_output_trace (u8 * s, va_list * va)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
+  vlib_node_t * node = va_arg (*va, vlib_node_t *);
+  interface_output_trace_t * t = va_arg (*va, interface_output_trace_t *);
+  vnet_main_t * vnm = vnet_get_main();
+  vnet_sw_interface_t * si;
+  uword indent;
+
+  if (t->sw_if_index != (u32)~0)
+    {
+      si = vnet_get_sw_interface (vnm, t->sw_if_index);
+      indent = format_get_indent (s);
+      
+      s = format (s, "%U\n%U%U",
+                  format_vnet_sw_interface_name, vnm, si,
+                  format_white_space, indent,
+                  node->format_buffer ? node->format_buffer : format_hex_bytes,
+                  t->data, sizeof (t->data));
+    }
+  return s;
+}
+
+static void
+vnet_interface_output_trace (vlib_main_t * vm,
+			     vlib_node_runtime_t * node,
+			     vlib_frame_t * frame,
+			     uword n_buffers)
+{
+  u32 n_left, * from;
+
+  n_left = n_buffers;
+  from = vlib_frame_args (frame);
+  
+  while (n_left >= 4)
+    {
+      u32 bi0, bi1;
+      vlib_buffer_t * b0, * b1;
+      interface_output_trace_t * t0, * t1;
+
+      /* Prefetch next iteration. */
+      vlib_prefetch_buffer_with_index (vm, from[2], LOAD);
+      vlib_prefetch_buffer_with_index (vm, from[3], LOAD);
+
+      bi0 = from[0];
+      bi1 = from[1];
+
+      b0 = vlib_get_buffer (vm, bi0);
+      b1 = vlib_get_buffer (vm, bi1);
+
+      if (b0->flags & VLIB_BUFFER_IS_TRACED)
+	{
+	  t0 = vlib_add_trace (vm, node, b0, sizeof (t0[0]));
+	  t0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_TX];
+	  memcpy (t0->data, vlib_buffer_get_current (b0),
+		  sizeof (t0->data));
+	}
+      if (b1->flags & VLIB_BUFFER_IS_TRACED)
+	{
+	  t1 = vlib_add_trace (vm, node, b1, sizeof (t1[0]));
+	  t1->sw_if_index = vnet_buffer (b1)->sw_if_index[VLIB_TX];
+	  memcpy (t1->data, vlib_buffer_get_current (b1),
+		  sizeof (t1->data));
+	}
+      from += 2;
+      n_left -= 2;
+    }
+
+  while (n_left >= 1)
+    {
+      u32 bi0;
+      vlib_buffer_t * b0;
+      interface_output_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[0]));
+	  t0->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_TX];
+	  memcpy (t0->data, vlib_buffer_get_current (b0),
+		  sizeof (t0->data));
+	}
+      from += 1;
+      n_left -= 1;
+    }
+}
+
+static never_inline u32
+slow_path (vlib_main_t * vm,
+	   u32 bi,
+	   vlib_buffer_t * b,
+	   u32 n_left_to_tx,
+	   u32 * to_tx,
+	   u32 * n_slow_bytes_result)
+{
+  /* We've already enqueued a single buffer. */
+  u32 n_buffers = 0;
+  u32 n_slow_bytes = 0;
+
+  while (n_left_to_tx > 0)
+    {
+      to_tx[0] = bi;
+      to_tx += 1;
+      n_left_to_tx -= 1;
+      n_buffers += 1;
+      n_slow_bytes += vlib_buffer_length_in_chain (vm, b);
+
+      /* Be grumpy about zero length buffers for benefit of
+	 driver tx function. */
+      ASSERT (b->current_length > 0);
+
+      if (! (b->flags & VLIB_BUFFER_NEXT_PRESENT))
+	break;
+
+      bi = b->next_buffer;
+      b = vlib_get_buffer (vm, bi);
+    }
+
+  /* Ran out of space in next frame trying to enqueue buffers? */
+  if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
+    return 0;
+
+  *n_slow_bytes_result = n_slow_bytes;
+  return n_buffers;
+}
+
+/* 
+ * Increment TX stats. Roll up consecutive increments to the same sw_if_index 
+ * into one increment.
+ */
+static_always_inline
+void incr_output_stats (vnet_main_t * vnm,
+                        u32 cpu_index, 
+                        u32 length, 
+                        u32 sw_if_index,
+                        u32 * last_sw_if_index, 
+                        u32 * n_packets, 
+                        u32 * n_bytes) {
+  vnet_interface_main_t * im;
+
+  if (PREDICT_TRUE (sw_if_index == *last_sw_if_index)) {
+    *n_packets += 1;
+    *n_bytes += length;
+  } else {
+    if (PREDICT_TRUE (*last_sw_if_index != ~0)) {
+      im = &vnm->interface_main;
+
+      vlib_increment_combined_counter (im->combined_sw_if_counters
+                                       + VNET_INTERFACE_COUNTER_TX,
+                                       cpu_index, 
+                                       *last_sw_if_index,
+				       *n_packets,
+				       *n_bytes);
+    }
+    *last_sw_if_index = sw_if_index;
+    *n_packets = 1;
+    *n_bytes = length;
+  }
+}
+
+
+/* Interface output functions. */
+uword
+vnet_interface_output_node (vlib_main_t * vm,
+			    vlib_node_runtime_t * node,
+			    vlib_frame_t * frame)
+{
+  vnet_main_t * vnm = vnet_get_main();
+  vnet_interface_output_runtime_t * rt = (void *) node->runtime_data;
+  vnet_sw_interface_t * si;
+  vnet_hw_interface_t * hi;
+  u32 n_left_to_tx, * from, * from_end, * to_tx;
+  u32 n_bytes, n_buffers, n_packets;
+  u32 last_sw_if_index;
+  u32 cpu_index = vm->cpu_index;
+
+  n_buffers = frame->n_vectors;
+
+  if (node->flags & VLIB_NODE_FLAG_TRACE)
+    vnet_interface_output_trace (vm, node, frame, n_buffers);
+
+  from = vlib_frame_args (frame);
+
+  if (rt->is_deleted)
+    return vlib_error_drop_buffers (vm, node,
+				    from,
+				    /* buffer stride */ 1,
+				    n_buffers,
+				    VNET_INTERFACE_OUTPUT_NEXT_DROP,
+				    node->node_index,
+				    VNET_INTERFACE_OUTPUT_ERROR_INTERFACE_DELETED);
+
+  si = vnet_get_sw_interface (vnm, rt->sw_if_index);
+  hi = vnet_get_sup_hw_interface (vnm, rt->sw_if_index);
+  if (! (si->flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP) ||
+      ! (hi->flags & VNET_HW_INTERFACE_FLAG_LINK_UP))
+    {
+      vlib_simple_counter_main_t * cm;
+     
+      cm = vec_elt_at_index (vnm->interface_main.sw_if_counters,
+                             VNET_INTERFACE_COUNTER_TX_ERROR);
+      vlib_increment_simple_counter (cm, cpu_index,
+                                     rt->sw_if_index, n_buffers);
+      return vlib_error_drop_buffers (vm, node,
+                                      from,
+                                      /* buffer stride */ 1,
+                                      n_buffers,
+                                      VNET_INTERFACE_OUTPUT_NEXT_DROP,
+                                      node->node_index,
+                                   VNET_INTERFACE_OUTPUT_ERROR_INTERFACE_DOWN);
+    }
+
+  from_end = from + n_buffers;
+
+  /* Total byte count of all buffers. */
+  n_bytes = 0;
+  n_packets = 0;
+  last_sw_if_index = ~0;
+
+  while (from < from_end)
+    {
+      /* Get new next frame since previous incomplete frame may have less
+	 than VNET_FRAME_SIZE vectors in it. */
+      vlib_get_new_next_frame (vm, node, VNET_INTERFACE_OUTPUT_NEXT_TX,
+			       to_tx, n_left_to_tx);
+
+      while (from + 4 <= from_end && n_left_to_tx >= 2)
+	{
+	  u32 bi0, bi1;
+	  vlib_buffer_t * b0, * b1;
+
+	  /* Prefetch next iteration. */
+	  vlib_prefetch_buffer_with_index (vm, from[2], LOAD);
+	  vlib_prefetch_buffer_with_index (vm, from[3], LOAD);
+
+	  bi0 = from[0];
+	  bi1 = from[1];
+	  to_tx[0] = bi0;
+	  to_tx[1] = bi1;
+	  from += 2;
+	  to_tx += 2;
+	  n_left_to_tx -= 2;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  b1 = vlib_get_buffer (vm, bi1);
+
+	  /* Be grumpy about zero length buffers for benefit of
+	     driver tx function. */
+	  ASSERT (b0->current_length > 0);
+	  ASSERT (b1->current_length > 0);
+
+	  if (PREDICT_FALSE ((b0->flags | b1->flags) & VLIB_BUFFER_NEXT_PRESENT))
+	    {
+	      u32 n_buffers, n_slow_bytes, i;
+
+	      /* Undo. */
+	      from -= 2;
+	      to_tx -= 2;
+	      n_left_to_tx += 2;
+
+	      /* Do slow path two times. */
+	      for (i = 0; i < 2; i++)
+		{
+		  u32 bi = i ? bi1 : bi0;
+		  vlib_buffer_t * b = i ? b1 : b0;
+
+		  n_buffers = slow_path (vm, bi, b,
+					 n_left_to_tx, to_tx, &n_slow_bytes);
+
+		  /* Not enough room for single packet? */
+		  if (n_buffers == 0)
+		    goto put;
+
+		  from += 1;
+		  to_tx += n_buffers;
+		  n_left_to_tx -= n_buffers;
+		  incr_output_stats (vnm, cpu_index, n_slow_bytes,
+				     vnet_buffer(b)->sw_if_index[VLIB_TX],
+                                     &last_sw_if_index, &n_packets, &n_bytes);
+		}
+            } else {
+	      incr_output_stats (vnm, cpu_index, 
+                                 vlib_buffer_length_in_chain (vm, b0),
+				 vnet_buffer(b0)->sw_if_index[VLIB_TX],
+                                 &last_sw_if_index, &n_packets, &n_bytes);
+	      incr_output_stats (vnm, cpu_index, 
+                                 vlib_buffer_length_in_chain (vm, b0),
+				 vnet_buffer(b1)->sw_if_index[VLIB_TX],
+                                 &last_sw_if_index, &n_packets, &n_bytes);
+            }
+	}
+
+      while (from + 1 <= from_end && n_left_to_tx >= 1)
+	{
+	  u32 bi0;
+	  vlib_buffer_t * b0;
+
+	  bi0 = from[0];
+	  to_tx[0] = bi0;
+	  from += 1;
+	  to_tx += 1;
+	  n_left_to_tx -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+
+	  /* Be grumpy about zero length buffers for benefit of
+	     driver tx function. */
+	  ASSERT (b0->current_length > 0);
+
+	  if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_NEXT_PRESENT))
+	    {
+	      u32 n_buffers, n_slow_bytes;
+
+	      /* Undo. */
+	      from -= 1;
+	      to_tx -= 1;
+	      n_left_to_tx += 1;
+
+	      n_buffers = slow_path (vm, bi0, b0,
+				     n_left_to_tx, to_tx, &n_slow_bytes);
+
+	      /* Not enough room for single packet? */
+	      if (n_buffers == 0)
+		goto put;
+
+	      from += 1;
+	      to_tx += n_buffers;
+	      n_left_to_tx -= n_buffers;
+	    }
+          incr_output_stats (vnm, cpu_index, 
+                             vlib_buffer_length_in_chain (vm, b0),
+			     vnet_buffer(b0)->sw_if_index[VLIB_TX],
+                             &last_sw_if_index, &n_packets, &n_bytes);
+	}
+
+    put:
+      vlib_put_next_frame (vm, node, VNET_INTERFACE_OUTPUT_NEXT_TX, n_left_to_tx);
+    }
+
+  /* Final update of interface stats. */
+  incr_output_stats (vnm, cpu_index, 0, ~0, /* ~0 will flush stats */
+                     &last_sw_if_index, &n_packets, &n_bytes); 
+
+  return n_buffers;
+}
+
+
+uword
+vnet_interface_output_node_no_flatten (vlib_main_t * vm,
+                                       vlib_node_runtime_t * node,
+                                       vlib_frame_t * frame)
+{
+  vnet_main_t * vnm = vnet_get_main();
+  vnet_interface_output_runtime_t * rt = (void *) node->runtime_data;
+  vnet_sw_interface_t * si;
+  vnet_hw_interface_t * hi;
+  u32 n_left_to_tx, * from, * from_end, * to_tx;
+  u32 n_bytes, n_buffers, n_packets;
+  u32 n_bytes_b0, n_bytes_b1;
+  u32 cpu_index = vm->cpu_index;
+  vnet_interface_main_t * im = &vnm->interface_main;
+  u32 next_index = VNET_INTERFACE_OUTPUT_NEXT_TX;
+
+  n_buffers = frame->n_vectors;
+
+  if (node->flags & VLIB_NODE_FLAG_TRACE)
+    vnet_interface_output_trace (vm, node, frame, n_buffers);
+
+  from = vlib_frame_args (frame);
+
+  if (rt->is_deleted)
+    return vlib_error_drop_buffers (vm, node,
+				    from,
+				    /* buffer stride */ 1,
+				    n_buffers,
+				    VNET_INTERFACE_OUTPUT_NEXT_DROP,
+				    node->node_index,
+				    VNET_INTERFACE_OUTPUT_ERROR_INTERFACE_DELETED);
+
+  si = vnet_get_sw_interface (vnm, rt->sw_if_index);
+  hi = vnet_get_sup_hw_interface (vnm, rt->sw_if_index);
+  if (! (si->flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP) ||
+      ! (hi->flags & VNET_HW_INTERFACE_FLAG_LINK_UP))
+    {
+      vlib_simple_counter_main_t * cm;
+     
+      cm = vec_elt_at_index (vnm->interface_main.sw_if_counters,
+                             VNET_INTERFACE_COUNTER_TX_ERROR);
+      vlib_increment_simple_counter (cm, cpu_index,
+                                     rt->sw_if_index, n_buffers);
+      
+      return vlib_error_drop_buffers (vm, node,
+                                      from,
+                                      /* buffer stride */ 1,
+                                      n_buffers,
+                                      VNET_INTERFACE_OUTPUT_NEXT_DROP,
+                                      node->node_index,
+                                      VNET_INTERFACE_OUTPUT_ERROR_INTERFACE_DOWN);
+    }
+
+  from_end = from + n_buffers;
+
+  /* Total byte count of all buffers. */
+  n_bytes = 0;
+  n_packets = 0;
+
+  while (from < from_end)
+    {
+      /* Get new next frame since previous incomplete frame may have less
+	 than VNET_FRAME_SIZE vectors in it. */
+      vlib_get_new_next_frame (vm, node, next_index,
+			       to_tx, n_left_to_tx);
+
+      while (from + 4 <= from_end && n_left_to_tx >= 2)
+	{
+	  u32 bi0, bi1;
+	  vlib_buffer_t * b0, * b1;
+          u32 tx_swif0, tx_swif1;
+
+	  /* Prefetch next iteration. */
+	  vlib_prefetch_buffer_with_index (vm, from[2], LOAD);
+	  vlib_prefetch_buffer_with_index (vm, from[3], LOAD);
+
+	  bi0 = from[0];
+	  bi1 = from[1];
+	  to_tx[0] = bi0;
+	  to_tx[1] = bi1;
+	  from += 2;
+	  to_tx += 2;
+	  n_left_to_tx -= 2;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  b1 = vlib_get_buffer (vm, bi1);
+
+	  /* Be grumpy about zero length buffers for benefit of
+	     driver tx function. */
+	  ASSERT (b0->current_length > 0);
+	  ASSERT (b1->current_length > 0);
+
+          n_bytes_b0 = vlib_buffer_length_in_chain (vm, b0);
+          n_bytes_b1 = vlib_buffer_length_in_chain (vm, b1);
+          tx_swif0 = vnet_buffer(b0)->sw_if_index[VLIB_TX];
+          tx_swif1 = vnet_buffer(b1)->sw_if_index[VLIB_TX];
+
+	  n_bytes += n_bytes_b0 + n_bytes_b1;
+	  n_packets += 2;
+
+          if (PREDICT_FALSE(si->output_feature_bitmap &&
+              vnet_buffer(b0)->output_features.bitmap != (1 << INTF_OUTPUT_FEAT_DONE)))
+            {
+              u32 next0;
+              vnet_buffer(b0)->output_features.bitmap = si->output_feature_bitmap;
+              count_trailing_zeros(next0, vnet_buffer(b0)->output_features.bitmap);
+              vnet_buffer(b0)->output_features.bitmap &= ~(1 << next0);
+              vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_tx,
+                                               n_left_to_tx, bi0, next0);
+            }
+          else
+            {
+              vnet_buffer(b0)->output_features.bitmap = 0;
+
+              if (PREDICT_FALSE(tx_swif0 != rt->sw_if_index))
+                {
+                  /* update vlan subif tx counts, if required */
+                  vlib_increment_combined_counter (im->combined_sw_if_counters
+                                                   + VNET_INTERFACE_COUNTER_TX,
+                                                   cpu_index,
+                                                   tx_swif0,
+                                                   1,
+                                                   n_bytes_b0);
+                }
+            }
+
+          if (PREDICT_FALSE(si->output_feature_bitmap &&
+              vnet_buffer(b1)->output_features.bitmap != (1 << INTF_OUTPUT_FEAT_DONE)))
+            {
+              u32 next1;
+              vnet_buffer(b1)->output_features.bitmap = si->output_feature_bitmap;
+              count_trailing_zeros(next1, vnet_buffer(b1)->output_features.bitmap);
+              vnet_buffer(b1)->output_features.bitmap &= ~(1 << next1);
+              vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_tx,
+                                               n_left_to_tx, bi1, next1);
+            }
+          else
+            {
+              vnet_buffer(b1)->output_features.bitmap = 0;
+
+              /* update vlan subif tx counts, if required */
+              if (PREDICT_FALSE(tx_swif1 != rt->sw_if_index))
+                {
+
+                  vlib_increment_combined_counter (im->combined_sw_if_counters
+                                                   + VNET_INTERFACE_COUNTER_TX,
+                                                   cpu_index,
+                                                   tx_swif1,
+                                                   1,
+                                                   n_bytes_b1);
+                }
+            }
+
+	}
+
+      while (from + 1 <= from_end && n_left_to_tx >= 1)
+	{
+	  u32 bi0;
+	  vlib_buffer_t * b0;
+          u32 tx_swif0;
+
+	  bi0 = from[0];
+	  to_tx[0] = bi0;
+	  from += 1;
+	  to_tx += 1;
+	  n_left_to_tx -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+
+	  /* Be grumpy about zero length buffers for benefit of
+	     driver tx function. */
+	  ASSERT (b0->current_length > 0);
+
+          n_bytes_b0 = vlib_buffer_length_in_chain (vm, b0);
+          tx_swif0 = vnet_buffer(b0)->sw_if_index[VLIB_TX];
+	  n_bytes += n_bytes_b0;
+	  n_packets += 1;
+
+          if (PREDICT_FALSE(si->output_feature_bitmap &&
+              vnet_buffer(b0)->output_features.bitmap != (1 << INTF_OUTPUT_FEAT_DONE)))
+            {
+              u32 next0;
+              vnet_buffer(b0)->output_features.bitmap = si->output_feature_bitmap;
+              count_trailing_zeros(next0, vnet_buffer(b0)->output_features.bitmap);
+              vnet_buffer(b0)->output_features.bitmap &= ~(1 << next0);
+              vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_tx,
+                                               n_left_to_tx, bi0, next0);
+            }
+          else
+            {
+              vnet_buffer(b0)->output_features.bitmap = 0;
+
+              if (PREDICT_FALSE(tx_swif0 != rt->sw_if_index))
+                {
+
+                  vlib_increment_combined_counter (im->combined_sw_if_counters
+                                                   + VNET_INTERFACE_COUNTER_TX,
+                                                   cpu_index,
+                                                   tx_swif0,
+                                                   1,
+                                                   n_bytes_b0);
+                }
+            }
+	}
+
+      vlib_put_next_frame (vm, node, next_index,
+                           n_left_to_tx);
+    }
+
+  /* Update main interface stats. */
+  vlib_increment_combined_counter (im->combined_sw_if_counters
+                                   + VNET_INTERFACE_COUNTER_TX,
+                                   cpu_index,
+                                   rt->sw_if_index,
+                                   n_packets,
+                                   n_bytes);
+  return n_buffers;
+}
+
+
+/* Use buffer's sw_if_index[VNET_TX] to choose output interface. */
+static uword
+vnet_per_buffer_interface_output (vlib_main_t * vm,
+				  vlib_node_runtime_t * node,
+				  vlib_frame_t * frame)
+{
+  vnet_main_t * vnm = vnet_get_main();
+  u32 n_left_to_next, * from, * to_next;
+  u32 n_left_from, next_index;
+
+  n_left_from = frame->n_vectors;
+
+  from = vlib_frame_args (frame);
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (n_left_from >= 4 && n_left_to_next >= 2)
+	{
+	  u32 bi0, bi1, next0, next1;
+	  vlib_buffer_t * b0, * b1;
+	  vnet_hw_interface_t * hi0, * hi1;
+
+	  /* Prefetch next iteration. */
+	  vlib_prefetch_buffer_with_index (vm, from[2], LOAD);
+	  vlib_prefetch_buffer_with_index (vm, from[3], LOAD);
+
+	  bi0 = from[0];
+	  bi1 = from[1];
+	  to_next[0] = bi0;
+	  to_next[1] = bi1;
+	  from += 2;
+	  to_next += 2;
+	  n_left_to_next -= 2;
+	  n_left_from -= 2;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  b1 = vlib_get_buffer (vm, bi1);
+
+	  hi0 = vnet_get_sup_hw_interface (vnm, vnet_buffer (b0)->sw_if_index[VLIB_TX]);
+	  hi1 = vnet_get_sup_hw_interface (vnm, vnet_buffer (b1)->sw_if_index[VLIB_TX]);
+
+	  next0 = hi0->hw_if_index;
+	  next1 = hi1->hw_if_index;
+
+	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index, to_next, n_left_to_next,
+					   bi0, bi1, next0, next1);
+	}
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 bi0, next0;
+	  vlib_buffer_t * b0;
+	  vnet_hw_interface_t * hi0;
+
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_to_next -= 1;
+	  n_left_from -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+
+	  hi0 = vnet_get_sup_hw_interface (vnm, vnet_buffer (b0)->sw_if_index[VLIB_TX]);
+
+	  next0 = hi0->hw_if_index;
+
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, n_left_to_next,
+					   bi0, next0);
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  return frame->n_vectors;
+}
+
+always_inline u32
+counter_index (vlib_main_t * vm, vlib_error_t e)
+{
+  vlib_node_t * n;
+  u32 ci, ni;
+
+  ni = vlib_error_get_node (e);
+  n = vlib_get_node (vm, ni);
+
+  ci = vlib_error_get_code (e);
+  ASSERT (ci < n->n_errors);
+
+  ci += n->error_heap_index;
+
+  return ci;
+}
+
+static u8 * format_vnet_error_trace (u8 * s, va_list * va)
+{
+  vlib_main_t * vm = va_arg (*va, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *);
+  vlib_error_t * e = va_arg (*va, vlib_error_t *);
+  vlib_node_t * error_node;
+  vlib_error_main_t * em = &vm->error_main;
+  u32 i;
+
+  error_node = vlib_get_node (vm, vlib_error_get_node (e[0]));
+  i = counter_index (vm, e[0]);
+  s = format (s, "%v: %s", error_node->name, em->error_strings_heap[i]);
+
+  return s;
+}
+
+static void
+trace_errors_with_buffers (vlib_main_t * vm,
+			   vlib_node_runtime_t * node,
+			   vlib_frame_t * frame)
+{
+  u32 n_left, * buffers;
+
+  buffers = vlib_frame_vector_args (frame);
+  n_left = frame->n_vectors;
+  
+  while (n_left >= 4)
+    {
+      u32 bi0, bi1;
+      vlib_buffer_t * b0, * b1;
+      vlib_error_t * t0, * t1;
+
+      /* Prefetch next iteration. */
+      vlib_prefetch_buffer_with_index (vm, buffers[2], LOAD);
+      vlib_prefetch_buffer_with_index (vm, buffers[3], LOAD);
+
+      bi0 = buffers[0];
+      bi1 = buffers[1];
+
+      b0 = vlib_get_buffer (vm, bi0);
+      b1 = vlib_get_buffer (vm, bi1);
+
+      if (b0->flags & VLIB_BUFFER_IS_TRACED)
+	{
+	  t0 = vlib_add_trace (vm, node, b0, sizeof (t0[0]));
+	  t0[0] = b0->error;
+	}
+      if (b1->flags & VLIB_BUFFER_IS_TRACED)
+	{
+	  t1 = vlib_add_trace (vm, node, b1, sizeof (t1[0]));
+	  t1[0] = b1->error;
+	}
+      buffers += 2;
+      n_left -= 2;
+    }
+
+  while (n_left >= 1)
+    {
+      u32 bi0;
+      vlib_buffer_t * b0;
+      vlib_error_t * t0;
+
+      bi0 = buffers[0];
+
+      b0 = vlib_get_buffer (vm, bi0);
+
+      if (b0->flags & VLIB_BUFFER_IS_TRACED)
+	{
+	  t0 = vlib_add_trace (vm, node, b0, sizeof (t0[0]));
+	  t0[0] = b0->error;
+	}
+      buffers += 1;
+      n_left -= 1;
+    }
+}
+
+static u8 *
+validate_error (vlib_main_t * vm, vlib_error_t * e, u32 index)
+{
+  uword node_index = vlib_error_get_node (e[0]);
+  uword code = vlib_error_get_code (e[0]);
+  vlib_node_t * n;
+
+  if (node_index >= vec_len (vm->node_main.nodes))
+    return format (0, "[%d], node index out of range 0x%x, error 0x%x",
+		   index, node_index, e[0]);
+
+  n = vlib_get_node (vm, node_index);
+  if (code >= n->n_errors)
+    return format (0, "[%d], code %d out of range for node %v",
+		   index, code, n->name);
+
+  return 0;
+}
+
+static u8 *
+validate_error_frame (vlib_main_t * vm,
+		      vlib_node_runtime_t * node,
+		      vlib_frame_t * f)
+{
+  u32 * buffers = vlib_frame_args (f);
+  vlib_buffer_t * b;
+  u8 * msg = 0;
+  uword i;
+
+  for (i = 0; i < f->n_vectors; i++)
+    {
+      b = vlib_get_buffer (vm, buffers[i]);
+      msg = validate_error (vm, &b->error, i);
+      if (msg)
+	return msg;
+    }
+
+  return msg;
+}
+
+typedef enum {
+  VNET_ERROR_DISPOSITION_DROP,
+  VNET_ERROR_DISPOSITION_PUNT,
+  VNET_ERROR_N_DISPOSITION,
+} vnet_error_disposition_t;
+
+always_inline void
+do_packet (vlib_main_t * vm, vlib_error_t a)
+{
+  vlib_error_main_t * em = &vm->error_main;
+  u32 i = counter_index (vm, a);
+  em->counters[i] += 1;
+  vlib_error_elog_count (vm, i, 1);
+}
+    
+static_always_inline uword
+process_drop_punt (vlib_main_t * vm,
+		   vlib_node_runtime_t * node,
+		   vlib_frame_t * frame,
+		   vnet_error_disposition_t disposition)
+{
+  vnet_main_t * vnm = vnet_get_main();
+  vlib_error_main_t * em = &vm->error_main;
+  u32 * buffers, * first_buffer;
+  vlib_error_t current_error;
+  u32 current_counter_index, n_errors_left;
+  u32 current_sw_if_index, n_errors_current_sw_if_index;
+  u64 current_counter;
+  vlib_simple_counter_main_t * cm;
+  u32 cpu_index = vm->cpu_index;
+
+  static vlib_error_t memory[VNET_ERROR_N_DISPOSITION];
+  static char memory_init[VNET_ERROR_N_DISPOSITION];
+
+  buffers = vlib_frame_args (frame);
+  first_buffer = buffers;
+
+  {
+    vlib_buffer_t * b = vlib_get_buffer (vm, first_buffer[0]);
+
+    if (! memory_init[disposition])
+      {
+	memory_init[disposition] = 1;
+	memory[disposition] = b->error;
+      }
+
+    current_sw_if_index = vnet_buffer (b)->sw_if_index[VLIB_RX];
+    n_errors_current_sw_if_index = 0;
+  }
+
+  current_error = memory[disposition];
+  current_counter_index = counter_index (vm, memory[disposition]);
+  current_counter = em->counters[current_counter_index];
+
+  if (node->flags & VLIB_NODE_FLAG_TRACE)
+    trace_errors_with_buffers (vm, node, frame);
+  
+  n_errors_left = frame->n_vectors;
+  cm = vec_elt_at_index (vnm->interface_main.sw_if_counters,
+			 (disposition == VNET_ERROR_DISPOSITION_PUNT
+			  ? VNET_INTERFACE_COUNTER_PUNT
+			  : VNET_INTERFACE_COUNTER_DROP));
+
+  while (n_errors_left >= 2)
+    {
+      vlib_buffer_t * b0, * b1;
+      vnet_sw_interface_t * sw_if0, * sw_if1;
+      vlib_error_t e0, e1;
+      u32 bi0, bi1;
+      u32 sw_if_index0, sw_if_index1;
+
+      bi0 = buffers[0];
+      bi1 = buffers[1];
+
+      buffers += 2;
+      n_errors_left -= 2;
+
+      b0 = vlib_get_buffer (vm, bi0);
+      b1 = vlib_get_buffer (vm, bi1);
+
+      e0 = b0->error;
+      e1 = b1->error;
+
+      sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+      sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
+
+      /* Speculate that sw_if_index == sw_if_index[01]. */
+      n_errors_current_sw_if_index += 2;
+
+      /* Speculatively assume all 2 (node, code) pairs are equal
+	 to current (node, code). */
+      current_counter += 2;
+
+      if (PREDICT_FALSE (e0 != current_error
+			 || e1 != current_error
+			 || sw_if_index0 != current_sw_if_index
+			 || sw_if_index1 != current_sw_if_index))
+	{
+	  current_counter -= 2;
+	  n_errors_current_sw_if_index -= 2;
+
+	  vlib_increment_simple_counter (cm, cpu_index, sw_if_index0, 1);
+	  vlib_increment_simple_counter (cm, cpu_index, sw_if_index1, 1);
+
+	  /* Increment super-interface drop/punt counters for
+	     sub-interfaces. */
+	  sw_if0 = vnet_get_sw_interface (vnm, sw_if_index0);
+	  vlib_increment_simple_counter
+              (cm, cpu_index, sw_if0->sup_sw_if_index,
+               sw_if0->sup_sw_if_index != sw_if_index0);
+
+	  sw_if1 = vnet_get_sw_interface (vnm, sw_if_index1);
+	  vlib_increment_simple_counter
+              (cm, cpu_index, sw_if1->sup_sw_if_index, 
+               sw_if1->sup_sw_if_index != sw_if_index1);
+
+	  em->counters[current_counter_index] = current_counter;
+	  do_packet (vm, e0);
+	  do_packet (vm, e1);
+
+	  /* For 2 repeated errors, change current error. */
+	  if (e0 == e1 && e1 != current_error)
+	    {
+	      current_error = e0;
+	      current_counter_index = counter_index (vm, e0);
+	    }
+	  current_counter = em->counters[current_counter_index];
+	}
+    }
+
+  while (n_errors_left >= 1)
+    {
+      vlib_buffer_t * b0;
+      vnet_sw_interface_t * sw_if0;
+      vlib_error_t e0;
+      u32 bi0, sw_if_index0;
+
+      bi0 = buffers[0];
+
+      buffers += 1;
+      n_errors_left -= 1;
+      current_counter += 1;
+
+      b0 = vlib_get_buffer (vm, bi0);
+      e0 = b0->error;
+
+      sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
+
+      /* Increment drop/punt counters. */
+      vlib_increment_simple_counter (cm, cpu_index, sw_if_index0, 1);
+
+      /* Increment super-interface drop/punt counters for sub-interfaces. */
+      sw_if0 = vnet_get_sw_interface (vnm, sw_if_index0);
+      vlib_increment_simple_counter (cm, cpu_index, sw_if0->sup_sw_if_index, 
+				     sw_if0->sup_sw_if_index != sw_if_index0);
+
+      if (PREDICT_FALSE (e0 != current_error))
+	{
+	  current_counter -= 1;
+
+	  vlib_error_elog_count (vm, current_counter_index,
+				 (current_counter
+				  - em->counters[current_counter_index]));
+	    
+	  em->counters[current_counter_index] = current_counter;
+
+	  do_packet (vm, e0);
+	  current_error = e0;
+	  current_counter_index = counter_index (vm, e0);
+	  current_counter = em->counters[current_counter_index];
+	}
+    }
+
+  if (n_errors_current_sw_if_index > 0)
+    {
+      vnet_sw_interface_t * si;
+
+      vlib_increment_simple_counter (cm, cpu_index, current_sw_if_index,
+				     n_errors_current_sw_if_index);
+
+      si = vnet_get_sw_interface (vnm, current_sw_if_index);
+      if (si->sup_sw_if_index != current_sw_if_index)
+          vlib_increment_simple_counter (cm, cpu_index, si->sup_sw_if_index,
+                                         n_errors_current_sw_if_index);
+    }
+
+  vlib_error_elog_count (vm, current_counter_index,
+			 (current_counter
+			  - em->counters[current_counter_index]));
+
+  /* Return cached counter. */
+  em->counters[current_counter_index] = current_counter;
+
+  /* Save memory for next iteration. */
+  memory[disposition] = current_error;
+
+  if (disposition == VNET_ERROR_DISPOSITION_DROP
+      || ! vm->os_punt_frame)
+    {
+      vlib_buffer_free
+	(vm,
+	 first_buffer,
+	 frame->n_vectors);
+
+      /* If there is no punt function, free the frame as well. */
+      if (disposition == VNET_ERROR_DISPOSITION_PUNT && ! vm->os_punt_frame)
+	vlib_frame_free (vm, node, frame);
+    }
+  else
+    vm->os_punt_frame (vm, node, frame);
+
+  return frame->n_vectors;
+}
+
+static inline void 
+pcap_drop_trace (vlib_main_t * vm, 
+                 vnet_interface_main_t * im, 
+                 vlib_frame_t * f)
+{
+  u32 * from;
+  u32 n_left = f->n_vectors;
+  vlib_buffer_t * b0, * p1;
+  u32 bi0;
+  i16 save_current_data;
+  u16 save_current_length;
+
+  from = vlib_frame_vector_args (f);
+
+  while (n_left > 0)
+    {
+      if (PREDICT_TRUE (n_left > 1))
+        {
+          p1 = vlib_get_buffer (vm, from[1]);
+          vlib_prefetch_buffer_header (p1, LOAD);
+        }
+      
+      bi0 = from[0];
+      b0 = vlib_get_buffer (vm, bi0);
+      from++;
+      n_left--;
+      
+      /* See if we're pointedly ignoring this specific error */
+      if (im->pcap_drop_filter_hash 
+          && hash_get (im->pcap_drop_filter_hash, b0->error))
+        continue;
+
+      /* Trace all drops, or drops received on a specific interface */
+      if (im->pcap_sw_if_index == 0 ||
+          im->pcap_sw_if_index == vnet_buffer(b0)->sw_if_index [VLIB_RX])
+        {
+          save_current_data = b0->current_data;
+          save_current_length = b0->current_length;
+          
+          /* 
+           * Typically, we'll need to rewind the buffer
+           */
+          if (b0->current_data > 0)
+            vlib_buffer_advance (b0, (word) -b0->current_data);
+
+          pcap_add_buffer (&im->pcap_main, vm, bi0, 512);
+
+          b0->current_data = save_current_data;
+          b0->current_length = save_current_length;
+        }
+    }
+}
+
+void vnet_pcap_drop_trace_filter_add_del (u32 error_index, int is_add)
+{
+  vnet_interface_main_t * im = &vnet_get_main()->interface_main;
+
+  if (im->pcap_drop_filter_hash == 0)
+      im->pcap_drop_filter_hash = hash_create (0, sizeof (uword));
+
+  if (is_add)
+    hash_set (im->pcap_drop_filter_hash, error_index, 1);
+  else
+    hash_unset (im->pcap_drop_filter_hash, error_index);
+}
+
+static uword
+process_drop (vlib_main_t * vm,
+	      vlib_node_runtime_t * node,
+	      vlib_frame_t * frame)
+{
+  vnet_interface_main_t * im = &vnet_get_main()->interface_main;
+
+  if (PREDICT_FALSE (im->drop_pcap_enable))
+    pcap_drop_trace (vm, im, frame);
+
+  return process_drop_punt (vm, node, frame, VNET_ERROR_DISPOSITION_DROP);
+}
+
+static uword
+process_punt (vlib_main_t * vm,
+	      vlib_node_runtime_t * node,
+	      vlib_frame_t * frame)
+{
+  return process_drop_punt (vm, node, frame, VNET_ERROR_DISPOSITION_PUNT);
+}
+
+VLIB_REGISTER_NODE (drop_buffers,static) = {
+  .function = process_drop,
+  .name = "error-drop",
+  .flags = VLIB_NODE_FLAG_IS_DROP,
+  .vector_size = sizeof (u32),
+  .format_trace = format_vnet_error_trace,
+  .validate_frame = validate_error_frame,
+};
+
+VLIB_REGISTER_NODE (punt_buffers,static) = {
+  .function = process_punt,
+  .flags = (VLIB_NODE_FLAG_FRAME_NO_FREE_AFTER_DISPATCH
+	    | VLIB_NODE_FLAG_IS_PUNT),
+  .name = "error-punt",
+  .vector_size = sizeof (u32),
+  .format_trace = format_vnet_error_trace,
+  .validate_frame = validate_error_frame,
+};
+
+static clib_error_t *
+vnet_per_buffer_interface_output_hw_interface_add_del (vnet_main_t * vnm,
+						       u32 hw_if_index,
+						       u32 is_create);
+
+VLIB_REGISTER_NODE (vnet_per_buffer_interface_output_node,static) = {
+  .function = vnet_per_buffer_interface_output,
+  .name = "interface-output",
+  .vector_size = sizeof (u32),
+};
+
+clib_error_t *
+vnet_per_buffer_interface_output_hw_interface_add_del (vnet_main_t * vnm,
+						       u32 hw_if_index,
+						       u32 is_create)
+{
+  vnet_hw_interface_t * hi = vnet_get_hw_interface (vnm, hw_if_index);
+  u32 next_index;
+
+  next_index = vlib_node_add_next_with_slot
+    (vnm->vlib_main, vnet_per_buffer_interface_output_node.index,
+     hi->output_node_index,
+     /* next_index */ hw_if_index);
+
+  ASSERT (next_index == hw_if_index);
+
+  return 0;
+}
+
+VNET_HW_INTERFACE_ADD_DEL_FUNCTION 
+(vnet_per_buffer_interface_output_hw_interface_add_del);
+
+static clib_error_t *
+pcap_drop_trace_command_fn (vlib_main_t * vm,
+                            unformat_input_t * input,
+                            vlib_cli_command_t * cmd)
+{
+  vnet_main_t * vnm = vnet_get_main();
+  vnet_interface_main_t * im = &vnm->interface_main;
+  u8 * filename;
+  u32 max;
+  int matched = 0;
+  clib_error_t * error = 0;
+
+  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT) 
+    {
+      if (unformat (input, "on"))
+        {
+          if (im->drop_pcap_enable == 0)
+            {
+              if (im->pcap_filename == 0)
+                im->pcap_filename = format (0, "/tmp/drop.pcap%c", 0);
+              
+              memset (&im->pcap_main, 0, sizeof (im->pcap_main));
+              im->pcap_main.file_name = (char *) im->pcap_filename;
+              im->pcap_main.n_packets_to_capture = 100;
+              if (im->pcap_pkts_to_capture)
+                im->pcap_main.n_packets_to_capture = im->pcap_pkts_to_capture;
+
+              im->pcap_main.packet_type = PCAP_PACKET_TYPE_ethernet;
+              im->drop_pcap_enable = 1;
+              matched = 1;
+              vlib_cli_output (vm, "pcap drop capture on...");
+            }
+          else
+            {
+              vlib_cli_output (vm, "pcap drop capture already on...");
+            }
+          matched = 1;
+        }
+      else if (unformat (input, "off"))
+        {
+          matched = 1;
+
+          if (im->drop_pcap_enable)
+            {
+              vlib_cli_output (vm, "captured %d pkts...", 
+                               im->pcap_main.n_packets_captured);
+              if (im->pcap_main.n_packets_captured)
+                {
+                  im->pcap_main.n_packets_to_capture = 
+                    im->pcap_main.n_packets_captured;
+                  error = pcap_write (&im->pcap_main);
+                  if (error)
+                    clib_error_report (error);
+                  else
+                    vlib_cli_output (vm, "saved to %s...", im->pcap_filename);
+                }
+            }
+          else
+            {
+              vlib_cli_output (vm, "pcap drop capture already off...");
+            }
+
+          im->drop_pcap_enable = 0;
+        }
+      else if (unformat (input, "max %d", &max))
+        {
+          im->pcap_pkts_to_capture = max;
+          matched = 1;
+        }
+
+      else if (unformat (input, "intfc %U", 
+                         unformat_vnet_sw_interface, vnm,
+                         &im->pcap_sw_if_index))
+        matched = 1;
+      else if (unformat (input, "intfc any"))
+        {
+          im->pcap_sw_if_index = 0;
+          matched = 1;
+        }
+      else if (unformat (input, "file %s", &filename))
+        {
+          u8 * chroot_filename;
+          /* Brain-police user path input */
+          if (strstr((char *)filename, "..") || index((char *)filename, '/'))
+            {
+              vlib_cli_output (vm, "illegal characters in filename '%s'", 
+                               filename);
+              continue;
+            }
+
+          chroot_filename = format (0, "/tmp/%s%c", filename, 0);
+          vec_free (filename);
+          
+          if (im->pcap_filename)
+            vec_free (im->pcap_filename);
+          vec_add1 (filename, 0);
+          im->pcap_filename = chroot_filename;
+          matched = 1;
+        }
+      else if (unformat (input, "status"))
+        {
+          if (im->drop_pcap_enable == 0)
+            {
+              vlib_cli_output (vm, "pcap drop capture is off...");
+              continue;
+            }
+
+          vlib_cli_output (vm, "pcap drop capture: %d of %d pkts...",
+                           im->pcap_main.n_packets_captured,
+                           im->pcap_main.n_packets_to_capture);
+          matched = 1;
+        }
+
+      else
+        break;
+    }
+
+  if (matched == 0)
+    return clib_error_return (0, "unknown input `%U'", 
+                              format_unformat_error, input);
+
+  return 0;
+}
+
+VLIB_CLI_COMMAND (pcap_trace_command, static) = {
+    .path = "pcap drop trace",
+    .short_help = 
+    "pcap drop trace on off max <nn> intfc <intfc> file <name> status",
+    .function = pcap_drop_trace_command_fn,
+};