Move the punt/drop nodes into vlib

The core VLIB library now has a means to dispoe of buffers.

the vlib punt/drop node counts node errors.
the vnet punt/drop node counts interface errors.

speed up both nodes with the usual reciepe.

before:
  error-drop   8.33e1

after:
  drop   4.51e1
  error-drop  6.81e0

Change-Id: If2e919458a3f2e9d71dbf9c6f1352dafb186a05b
Signed-off-by: Neale Ranns <nranns@cisco.com>

2 files changed, 287 insertions, 0 deletions

diff --git a/src/vlib/CMakeLists.txt b/src/vlib/CMakeLists.txt
index 86fc965ba97..ff64baea980 100644
--- a/src/vlib/CMakeLists.txt
+++ b/src/vlib/CMakeLists.txt
@@ -49,6 +49,7 @@ add_vpp_library(vlib
   buffer.c
   cli.c
   counter.c
+  drop.c
   error.c
   format.c
   i2c.c
@@ -74,6 +75,9 @@ add_vpp_library(vlib
   vmbus/vmbus.c
   ${VMBUS_SOURCE}
 
+  MULTIARCH_SOURCES
+  drop.c
+
   INSTALL_HEADERS
   buffer_funcs.h
   buffer.h
diff --git a/src/vlib/drop.c b/src/vlib/drop.c
new file mode 100644
index 00000000000..2b245b561e3
--- /dev/null
+++ b/src/vlib/drop.c
@@ -0,0 +1,283 @@
+/*
+ * drop.c - Punt and drop nodes
+ *
+ * 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.
+ */
+
+#include <vlib/vlib.h>
+
+typedef enum
+{
+  ERROR_DISPOSITION_DROP,
+  ERROR_DISPOSITION_PUNT,
+  ERROR_N_DISPOSITION,
+} error_disposition_t;
+
+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_vector_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;
+}
+
+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_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 (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_always_inline uword
+process_drop_punt (vlib_main_t * vm,
+		   vlib_node_runtime_t * node,
+		   vlib_frame_t * frame, error_disposition_t disposition)
+{
+  u32 errors[VLIB_FRAME_SIZE], *error, *from, n_left;
+  vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
+  vlib_error_main_t *em = &vm->error_main;
+
+  from = vlib_frame_vector_args (frame);
+  n_left = frame->n_vectors;
+  b = bufs;
+  error = errors;
+
+  vlib_get_buffers (vm, from, bufs, n_left);
+
+  if (node->flags & VLIB_NODE_FLAG_TRACE)
+    trace_errors (vm, node, frame);
+
+  /* collect the array of error first ... */
+  while (n_left >= 4)
+    {
+      if (n_left >= 12)
+	{
+	  /* Prefetch 8 ahead - there's not much going on in each iteration */
+	  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);
+	}
+      error[0] = b[0]->error;
+      error[1] = b[1]->error;
+      error[2] = b[2]->error;
+      error[3] = b[3]->error;
+
+      error += 4;
+      n_left -= 4;
+      b += 4;
+    }
+  while (n_left)
+    {
+      error[0] = b[0]->error;
+
+      error += 1;
+      n_left -= 1;
+      b += 1;
+    }
+
+  /* ... then count against them in blocks */
+  n_left = frame->n_vectors;
+
+  while (n_left)
+    {
+      u16 off, count;
+      u32 c_index;
+
+      off = frame->n_vectors - n_left;
+
+      error = errors + off;
+
+      count = clib_count_equal_u32 (error, n_left);
+      n_left -= count;
+
+      c_index = counter_index (vm, error[0]);
+      em->counters[c_index] += count;
+
+      vlib_error_elog_count (vm, c_index, count);
+    }
+
+  if (disposition == ERROR_DISPOSITION_DROP || !vm->os_punt_frame)
+    {
+      vlib_buffer_free (vm, from, frame->n_vectors);
+
+      /* If there is no punt function, free the frame as well. */
+      if (disposition == 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;
+}
+
+VLIB_NODE_FN (error_drop_node) (vlib_main_t * vm,
+				vlib_node_runtime_t * node,
+				vlib_frame_t * frame)
+{
+  return process_drop_punt (vm, node, frame, ERROR_DISPOSITION_DROP);
+}
+
+VLIB_NODE_FN (error_punt_node) (vlib_main_t * vm,
+				vlib_node_runtime_t * node,
+				vlib_frame_t * frame)
+{
+  return process_drop_punt (vm, node, frame, ERROR_DISPOSITION_PUNT);
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (error_drop_node) = {
+  .name = "drop",
+  .flags = VLIB_NODE_FLAG_IS_DROP,
+  .vector_size = sizeof (u32),
+  .format_trace = format_error_trace,
+  .validate_frame = validate_error_frame,
+};
+/* *INDENT-ON* */
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (error_punt_node) = {
+  .name = "punt",
+  .flags = (VLIB_NODE_FLAG_FRAME_NO_FREE_AFTER_DISPATCH
+	    | VLIB_NODE_FLAG_IS_PUNT),
+  .vector_size = sizeof (u32),
+  .format_trace = format_error_trace,
+  .validate_frame = validate_error_frame,
+};
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */