dispatch-trace: move dispatch trace pcap code to plugin

Type: refactor
Change-Id: I02a527f57853ebff797f0d85761b71127916d6ce
Signed-off-by: Damjan Marion <damarion@cisco.com>

10 files changed, 614 insertions, 573 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 67268fbfbed..27b6b291554 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -394,6 +394,11 @@ I:	avf
 M:	Damjan Marion <damarion@cisco.com>
 F:	src/plugins/avf/
 
+Plugin - Dispatch Trace PCAP
+I:	dispatch-trace
+M:	Dave Barach <vpp@barachs.net>
+F:	src/plugins/dispatch-trace
+
 Plugin - DPDK
 I:	dpdk
 M:	Damjan Marion <damarion@cisco.com>
diff --git a/src/plugins/dispatch-trace/CMakeLists.txt b/src/plugins/dispatch-trace/CMakeLists.txt
new file mode 100644
index 00000000000..5ba47f9aba3
--- /dev/null
+++ b/src/plugins/dispatch-trace/CMakeLists.txt
@@ -0,0 +1,17 @@
+# Copyright (c) 2018 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.
+
+add_vpp_plugin(dispatch_trace
+  SOURCES
+  main.c
+)
diff --git a/src/plugins/dispatch-trace/main.c b/src/plugins/dispatch-trace/main.c
new file mode 100644
index 00000000000..0650997889d
--- /dev/null
+++ b/src/plugins/dispatch-trace/main.c
@@ -0,0 +1,506 @@
+/* SPDX-License-Identifier: Apache-2.0
+ * Copyright(c) 2021 Cisco Systems, Inc.
+ */
+
+#include <vnet/plugin/plugin.h>
+#include <vpp/app/version.h>
+
+typedef struct
+{
+  u8 *pcap_buffer;
+} dispatch_trace_thread_t;
+
+typedef struct
+{
+  u32 enable : 1;
+  pcap_main_t dispatch_pcap_main;
+  u32 *dispatch_buffer_trace_nodes;
+  dispatch_trace_thread_t *threads;
+  u32 epoll_input_node_index;
+} dispatch_trace_main_t;
+
+dispatch_trace_main_t dispatch_trace_main;
+
+#define VLIB_PCAP_MAJOR_VERSION 1
+#define VLIB_PCAP_MINOR_VERSION 0
+
+typedef struct
+{
+  u8 *filename;
+  int enable;
+  int status;
+  int post_mortem;
+  u32 packets_to_capture;
+  u32 buffer_trace_node_index;
+  u32 buffer_traces_to_capture;
+} vlib_pcap_dispatch_trace_args_t;
+
+static u8 *
+format_buffer_metadata (u8 *s, va_list *args)
+{
+  vlib_buffer_t *b = va_arg (*args, vlib_buffer_t *);
+
+  s = format (s, "flags: %U\n", format_vnet_buffer_flags, b);
+  s = format (s, "current_data: %d, current_length: %d\n",
+	      (i32) (b->current_data), (i32) (b->current_length));
+  s = format (
+    s, "current_config_index/punt_reason: %d, flow_id: %x, next_buffer: %x\n",
+    b->current_config_index, b->flow_id, b->next_buffer);
+  s = format (s, "error: %d, ref_count: %d, buffer_pool_index: %d\n",
+	      (u32) (b->error), (u32) (b->ref_count),
+	      (u32) (b->buffer_pool_index));
+  s = format (s, "trace_handle: 0x%x, len_not_first_buf: %d\n",
+	      b->trace_handle, b->total_length_not_including_first_buffer);
+  return s;
+}
+
+#define A(x) vec_add1 (dtt->pcap_buffer, (x))
+
+uword
+dispatch_pcap_trace (vlib_main_t *vm, vlib_node_runtime_t *node,
+		     vlib_frame_t *frame)
+{
+  int i;
+  vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **bufp, *b;
+  dispatch_trace_main_t *dtm = &dispatch_trace_main;
+  pcap_main_t *pm = &dtm->dispatch_pcap_main;
+  dispatch_trace_thread_t *dtt =
+    vec_elt_at_index (dtm->threads, vm->thread_index);
+  vlib_trace_main_t *tm = &vm->trace_main;
+  u32 capture_size;
+  vlib_node_t *n;
+  i32 n_left;
+  f64 time_now = vlib_time_now (vm);
+  u32 *from;
+  u8 *d;
+  u8 string_count;
+
+  /* Input nodes don't have frames yet */
+  if (frame == 0 || frame->n_vectors == 0)
+    goto done;
+
+  from = vlib_frame_vector_args (frame);
+  vlib_get_buffers (vm, from, bufs, frame->n_vectors);
+  bufp = bufs;
+
+  n = vlib_get_node (vm, node->node_index);
+
+  for (i = 0; i < frame->n_vectors; i++)
+    {
+      if (PREDICT_TRUE (pm->n_packets_captured < pm->n_packets_to_capture))
+	{
+	  b = bufp[i];
+
+	  vec_reset_length (dtt->pcap_buffer);
+	  string_count = 0;
+
+	  /* Version, flags */
+	  A ((u8) VLIB_PCAP_MAJOR_VERSION);
+	  A ((u8) VLIB_PCAP_MINOR_VERSION);
+	  A (0 /* string_count */);
+	  A (n->protocol_hint);
+
+	  /* Buffer index (big endian) */
+	  A ((from[i] >> 24) & 0xff);
+	  A ((from[i] >> 16) & 0xff);
+	  A ((from[i] >> 8) & 0xff);
+	  A ((from[i] >> 0) & 0xff);
+
+	  /* Node name, NULL-terminated ASCII */
+	  dtt->pcap_buffer = format (dtt->pcap_buffer, "%v%c", n->name, 0);
+	  string_count++;
+
+	  dtt->pcap_buffer =
+	    format (dtt->pcap_buffer, "%U%c", format_buffer_metadata, b, 0);
+	  string_count++;
+	  dtt->pcap_buffer =
+	    format (dtt->pcap_buffer, "%U%c", format_vnet_buffer_opaque, b, 0);
+	  string_count++;
+	  dtt->pcap_buffer = format (dtt->pcap_buffer, "%U%c",
+				     format_vnet_buffer_opaque2, b, 0);
+	  string_count++;
+
+	  /* Is this packet traced? */
+	  if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
+	    {
+	      vlib_trace_header_t **h = pool_elt_at_index (
+		tm->trace_buffer_pool, vlib_buffer_get_trace_index (b));
+
+	      dtt->pcap_buffer = format (dtt->pcap_buffer, "%U%c",
+					 format_vlib_trace, vm, h[0], 0);
+	      string_count++;
+	    }
+
+	  /* Save the string count */
+	  dtt->pcap_buffer[2] = string_count;
+
+	  /* Figure out how many bytes in the pcap trace */
+	  capture_size =
+	    vec_len (dtt->pcap_buffer) + +vlib_buffer_length_in_chain (vm, b);
+
+	  clib_spinlock_lock_if_init (&pm->lock);
+	  n_left = clib_min (capture_size, 16384);
+	  d = pcap_add_packet (pm, time_now, n_left, capture_size);
+
+	  /* Copy the header */
+	  clib_memcpy_fast (d, dtt->pcap_buffer, vec_len (dtt->pcap_buffer));
+	  d += vec_len (dtt->pcap_buffer);
+
+	  n_left = clib_min (vlib_buffer_length_in_chain (vm, b),
+			     (16384 - vec_len (dtt->pcap_buffer)));
+	  /* Copy the packet data */
+	  while (1)
+	    {
+	      u32 copy_length = clib_min ((u32) n_left, b->current_length);
+	      clib_memcpy_fast (d, b->data + b->current_data, copy_length);
+	      n_left -= b->current_length;
+	      if (n_left <= 0)
+		break;
+	      d += b->current_length;
+	      ASSERT (b->flags & VLIB_BUFFER_NEXT_PRESENT);
+	      b = vlib_get_buffer (vm, b->next_buffer);
+	    }
+	  clib_spinlock_unlock_if_init (&pm->lock);
+	}
+    }
+done:
+  return node->function (vm, node, frame);
+}
+
+static void
+pcap_postmortem_reset (vlib_main_t *vm)
+{
+  dispatch_trace_main_t *dtm = &dispatch_trace_main;
+  pcap_main_t *pm = &dtm->dispatch_pcap_main;
+
+  /* Reset the trace buffer and capture count */
+  clib_spinlock_lock_if_init (&pm->lock);
+  vec_reset_length (pm->pcap_data);
+  pm->n_packets_captured = 0;
+  if (vec_len (vlib_worker_threads) == 1 && dtm->epoll_input_node_index)
+    {
+      vlib_node_runtime_t *epoll_input_rt =
+	vlib_node_get_runtime (vm, dtm->epoll_input_node_index);
+      epoll_input_rt->input_main_loops_per_call = 0;
+    }
+  clib_spinlock_unlock_if_init (&pm->lock);
+}
+
+static void
+pcap_postmortem_dump (void)
+{
+  dispatch_trace_main_t *dtm = &dispatch_trace_main;
+  pcap_main_t *pm = &dtm->dispatch_pcap_main;
+  clib_error_t *error;
+
+  pm->n_packets_to_capture = pm->n_packets_captured;
+  pm->file_name =
+    (char *) format (0, "/tmp/dispatch_post_mortem.%d%c", getpid (), 0);
+  error = pcap_write (pm);
+  pcap_close (pm);
+  if (error)
+    clib_error_report (error);
+  /*
+   * We're in the middle of crashing. Don't try to free the filename.
+   */
+}
+static int
+vlib_pcap_dispatch_trace_configure (vlib_pcap_dispatch_trace_args_t *a)
+{
+  vlib_main_t *vm = vlib_get_main ();
+  vlib_thread_main_t *vtm = vlib_get_thread_main ();
+  dispatch_trace_main_t *dtm = &dispatch_trace_main;
+  pcap_main_t *pm = &dtm->dispatch_pcap_main;
+  vlib_trace_main_t *tm;
+  vlib_trace_node_t *tn;
+
+  vec_validate (dtm->threads, vtm->n_vlib_mains);
+
+  if (a->status)
+    {
+      if (dtm->enable)
+	{
+	  int i;
+	  vlib_cli_output (vm,
+			   "pcap dispatch capture enabled: %d of %d pkts...",
+			   pm->n_packets_captured, pm->n_packets_to_capture);
+	  vlib_cli_output (vm, "capture to file %s", pm->file_name);
+
+	  for (i = 0; i < vec_len (dtm->dispatch_buffer_trace_nodes); i++)
+	    {
+	      vlib_cli_output (
+		vm, "Buffer trace of %d pkts from %U enabled...",
+		a->buffer_traces_to_capture, format_vlib_node_name, vm,
+		dtm->dispatch_buffer_trace_nodes[i]);
+	    }
+	}
+      else
+	vlib_cli_output (vm, "pcap dispatch capture disabled");
+      return 0;
+    }
+
+  /* Consistency checks */
+
+  /* Enable w/ capture already enabled not allowed */
+  if (dtm->enable && a->enable)
+    return VNET_API_ERROR_INVALID_VALUE;
+
+  /* Disable capture with capture already disabled, not interesting */
+  if (dtm->enable == 0 && a->enable == 0)
+    return VNET_API_ERROR_VALUE_EXIST;
+
+  /* Change number of packets to capture while capturing */
+  if (dtm->enable && a->enable &&
+      (pm->n_packets_to_capture != a->packets_to_capture))
+    return VNET_API_ERROR_INVALID_VALUE_2;
+
+  /* Independent of enable/disable, to allow buffer trace multi nodes */
+  if (a->buffer_trace_node_index != ~0)
+    {
+      foreach_vlib_main (({
+	tm = &this_vlib_main->trace_main;
+	tm->verbose = 0; /* not sure this ever did anything... */
+	vec_validate (tm->nodes, a->buffer_trace_node_index);
+	tn = tm->nodes + a->buffer_trace_node_index;
+	tn->limit += a->buffer_traces_to_capture;
+	if (a->post_mortem)
+	  {
+	    tm->filter_flag = FILTER_FLAG_POST_MORTEM;
+	    tm->filter_count = ~0;
+	  }
+	tm->trace_enable = 1;
+	if (vlib_node_set_dispatch_wrapper (this_vlib_main,
+					    dispatch_pcap_trace))
+	  clib_warning (0, "Dispatch wrapper already in use on thread %u",
+			this_vlib_main->thread_index);
+      }));
+      vec_add1 (dtm->dispatch_buffer_trace_nodes, a->buffer_trace_node_index);
+    }
+
+  if (a->enable)
+    {
+      /* Clean up from previous run, if any */
+      vec_free (pm->file_name);
+      vec_free (pm->pcap_data);
+      memset (pm, 0, sizeof (*pm));
+
+      vec_validate_aligned (vnet_trace_placeholder, 2048,
+			    CLIB_CACHE_LINE_BYTES);
+      if (pm->lock == 0)
+	clib_spinlock_init (&(pm->lock));
+
+      if (a->filename == 0)
+	a->filename = format (0, "/tmp/dispatch.pcap%c", 0);
+
+      pm->file_name = (char *) a->filename;
+      pm->n_packets_captured = 0;
+      pm->packet_type = PCAP_PACKET_TYPE_vpp;
+      pm->n_packets_to_capture = a->packets_to_capture;
+      dtm->enable = 1;
+    }
+  else
+    {
+      dtm->enable = 0;
+      foreach_vlib_main (({
+	tm = &this_vlib_main->trace_main;
+	tm->filter_flag = 0;
+	tm->filter_count = 0;
+	vlib_node_set_dispatch_wrapper (this_vlib_main, 0);
+      }));
+      vec_reset_length (dtm->dispatch_buffer_trace_nodes);
+      if (pm->n_packets_captured)
+	{
+	  clib_error_t *error;
+	  pm->n_packets_to_capture = pm->n_packets_captured;
+	  vlib_cli_output (vm, "Write %d packets to %s, and stop capture...",
+			   pm->n_packets_captured, pm->file_name);
+	  error = pcap_write (pm);
+	  if (pm->flags & PCAP_MAIN_INIT_DONE)
+	    pcap_close (pm);
+	  /* Report I/O errors... */
+	  if (error)
+	    {
+	      clib_error_report (error);
+	      return VNET_API_ERROR_SYSCALL_ERROR_1;
+	    }
+	  return 0;
+	}
+      else
+	return VNET_API_ERROR_NO_SUCH_ENTRY;
+    }
+
+  vlib_node_t *epoll_input_node =
+    vlib_get_node_by_name (vm, (u8 *) "unix-epoll-input");
+
+  /* Save the input node index, see the post-mortem callback */
+  if (epoll_input_node)
+    dtm->epoll_input_node_index = epoll_input_node->index;
+
+  /* main thread only */
+  clib_callback_enable_disable (vm->worker_thread_main_loop_callbacks,
+				vm->worker_thread_main_loop_callback_tmp,
+				vm->worker_thread_main_loop_callback_lock,
+				pcap_postmortem_reset, a->post_mortem);
+  vlib_add_del_post_mortem_callback (pcap_postmortem_dump, a->post_mortem);
+
+  return 0;
+}
+
+static clib_error_t *
+dispatch_trace_command_fn (vlib_main_t *vm, unformat_input_t *input,
+			   vlib_cli_command_t *cmd)
+{
+  unformat_input_t _line_input, *line_input = &_line_input;
+  vlib_pcap_dispatch_trace_args_t _a, *a = &_a;
+  u8 *filename = 0;
+  u32 max = 1000;
+  int rv;
+  int enable = 0;
+  int status = 0;
+  int post_mortem = 0;
+  u32 node_index = ~0, buffer_traces_to_capture = 100;
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "on %=", &enable, 1))
+	;
+      else if (unformat (line_input, "enable %=", &enable, 1))
+	;
+      else if (unformat (line_input, "off %=", &enable, 0))
+	;
+      else if (unformat (line_input, "disable %=", &enable, 0))
+	;
+      else if (unformat (line_input, "max %d", &max))
+	;
+      else if (unformat (line_input, "packets-to-capture %d", &max))
+	;
+      else if (unformat (line_input, "file %U", unformat_vlib_tmpfile,
+			 &filename))
+	;
+      else if (unformat (line_input, "status %=", &status, 1))
+	;
+      else if (unformat (line_input, "buffer-trace %U %d", unformat_vlib_node,
+			 vm, &node_index, &buffer_traces_to_capture))
+	;
+      else if (unformat (line_input, "post-mortem %=", &post_mortem, 1))
+	;
+      else
+	{
+	  return clib_error_return (0, "unknown input `%U'",
+				    format_unformat_error, line_input);
+	}
+    }
+
+  unformat_free (line_input);
+
+  /* no need for memset (a, 0, sizeof (*a)), set all fields here. */
+  a->filename = filename;
+  a->enable = enable;
+  a->status = status;
+  a->packets_to_capture = max;
+  a->buffer_trace_node_index = node_index;
+  a->buffer_traces_to_capture = buffer_traces_to_capture;
+  a->post_mortem = post_mortem;
+
+  rv = vlib_pcap_dispatch_trace_configure (a);
+
+  switch (rv)
+    {
+    case 0:
+      break;
+
+    case -7:
+      return clib_error_return (0, "dispatch trace already enabled...");
+
+    case -81:
+      return clib_error_return (0, "dispatch trace already disabled...");
+
+    case -8:
+      return clib_error_return (
+	0, "can't change number of records to capture while tracing...");
+
+    case -11:
+      return clib_error_return (0, "I/O writing trace capture...");
+
+    case -6:
+      return clib_error_return (0, "No packets captured...");
+
+    default:
+      vlib_cli_output (vm, "WARNING: trace configure returned %d", rv);
+      break;
+    }
+  return 0;
+}
+
+/*?
+ * This command is used to start or stop pcap dispatch trace capture, or show
+ * the capture status.
+ *
+ * This command has the following optional parameters:
+ *
+ * - <b>on|off</b> - Used to start or stop capture.
+ *
+ * - <b>max <nn></b> - Depth of local buffer. Once '<em>nn</em>' number
+ *   of packets have been received, buffer is flushed to file. Once another
+ *   '<em>nn</em>' number of packets have been received, buffer is flushed
+ *   to file, overwriting previous write. If not entered, value defaults
+ *   to 100. Can only be updated if packet capture is off.
+ *
+ * - <b>file <name></b> - Used to specify the output filename. The file will
+ *   be placed in the '<em>/tmp</em>' directory, so only the filename is
+ *   supported. Directory should not be entered. If file already exists, file
+ *   will be overwritten. If no filename is provided, '<em>/tmp/vpe.pcap</em>'
+ *   will be used. Can only be updated if packet capture is off.
+ *
+ * - <b>status</b> - Displays the current status and configured attributes
+ *   associated with a packet capture. If packet capture is in progress,
+ *   '<em>status</em>' also will return the number of packets currently in
+ *   the local buffer. All additional attributes entered on command line
+ *   with '<em>status</em>' will be ignored and not applied.
+ *
+ * @cliexpar
+ * Example of how to display the status of capture when off:
+ * @cliexstart{pcap dispatch trace status}
+ * max is 100, for any interface to file /tmp/vpe.pcap
+ * pcap dispatch capture is off...
+ * @cliexend
+ * Example of how to start a dispatch trace capture:
+ * @cliexstart{pcap dispatch trace on max 35 file dispatchTrace.pcap}
+ * pcap dispatch capture on...
+ * @cliexend
+ * Example of how to start a dispatch trace capture with buffer tracing
+ * @cliexstart{pcap dispatch trace on max 10000 file dispatchTrace.pcap
+ *   buffer-trace dpdk-input 1000}
+ * pcap dispatch capture on...
+ * @cliexend
+ * Example of how to display the status of a tx packet capture in progress:
+ * @cliexstart{pcap tx trace status}
+ * max is 35, dispatch trace to file /tmp/vppTest.pcap
+ * pcap tx capture is on: 20 of 35 pkts...
+ * @cliexend
+ * Example of how to stop a tx packet capture:
+ * @cliexstart{vppctl pcap dispatch trace off}
+ * captured 21 pkts...
+ * saved to /tmp/dispatchTrace.pcap...
+ * Example of how to start a post-mortem dispatch trace:
+ * pcap dispatch trace on max 20000 buffer-trace
+ *     dpdk-input 3000000000 post-mortem
+ * @cliexend
+?*/
+
+VLIB_CLI_COMMAND (pcap_dispatch_trace_command, static) = {
+  .path = "pcap dispatch trace",
+  .short_help =
+    "pcap dispatch trace [on|off] [max <nn>] [file <name>] [status]\n"
+    "              [buffer-trace <input-node-name> <nn>][post-mortem]",
+  .function = dispatch_trace_command_fn,
+};
+
+VLIB_PLUGIN_REGISTER () = {
+  .version = VPP_BUILD_VER,
+  .description = "Dispatch Trace",
+};
diff --git a/src/vlib/main.c b/src/vlib/main.c
index 761d4ee0bc5..111941ce90a 100644
--- a/src/vlib/main.c
+++ b/src/vlib/main.c
@@ -742,41 +742,9 @@ void
 vlib_post_mortem_dump (void)
 {
   vlib_main_t *vm = &vlib_global_main;
-  elog_main_t *em = &vm->elog_main;
-
-  u8 *filename;
-  clib_error_t *error;
-
-  if ((vm->elog_post_mortem_dump + vm->dispatch_pcap_postmortem) == 0)
-    return;
-
-  if (vm->dispatch_pcap_postmortem)
-    {
-      clib_error_t *error;
-      pcap_main_t *pm = &vm->dispatch_pcap_main;
-
-      pm->n_packets_to_capture = pm->n_packets_captured;
-      pm->file_name = (char *) format (0, "/tmp/dispatch_post_mortem.%d%c",
-				       getpid (), 0);
-      error = pcap_write (pm);
-      pcap_close (pm);
-      if (error)
-	clib_error_report (error);
-      /*
-       * We're in the middle of crashing. Don't try to free the filename.
-       */
-    }
 
-  if (vm->elog_post_mortem_dump)
-    {
-      filename = format (0, "/tmp/elog_post_mortem.%d%c", getpid (), 0);
-      error = elog_write_file (em, (char *) filename, 1 /* flush ring */ );
-      if (error)
-	clib_error_report (error);
-      /*
-       * We're in the middle of crashing. Don't try to free the filename.
-       */
-    }
+  for (int i = 0; i < vec_len (vm->post_mortem_callbacks); i++)
+    (vm->post_mortem_callbacks[i]) ();
 }
 
 /* *INDENT-OFF* */
@@ -986,163 +954,6 @@ add_trajectory_trace (vlib_buffer_t * b, u32 node_index)
 #endif
 }
 
-u8 *format_vnet_buffer_flags (u8 * s, va_list * args) __attribute__ ((weak));
-u8 *
-format_vnet_buffer_flags (u8 * s, va_list * args)
-{
-  s = format (s, "BUG STUB %s", __FUNCTION__);
-  return s;
-}
-
-u8 *format_vnet_buffer_opaque (u8 * s, va_list * args) __attribute__ ((weak));
-u8 *
-format_vnet_buffer_opaque (u8 * s, va_list * args)
-{
-  s = format (s, "BUG STUB %s", __FUNCTION__);
-  return s;
-}
-
-u8 *format_vnet_buffer_opaque2 (u8 * s, va_list * args)
-  __attribute__ ((weak));
-u8 *
-format_vnet_buffer_opaque2 (u8 * s, va_list * args)
-{
-  s = format (s, "BUG STUB %s", __FUNCTION__);
-  return s;
-}
-
-static u8 *
-format_buffer_metadata (u8 * s, va_list * args)
-{
-  vlib_buffer_t *b = va_arg (*args, vlib_buffer_t *);
-
-  s = format (s, "flags: %U\n", format_vnet_buffer_flags, b);
-  s = format (s, "current_data: %d, current_length: %d\n",
-	      (i32) (b->current_data), (i32) (b->current_length));
-  s = format
-    (s,
-     "current_config_index/punt_reason: %d, flow_id: %x, next_buffer: %x\n",
-     b->current_config_index, b->flow_id, b->next_buffer);
-  s =
-    format (s, "error: %d, ref_count: %d, buffer_pool_index: %d\n",
-	    (u32) (b->error), (u32) (b->ref_count),
-	    (u32) (b->buffer_pool_index));
-  s =
-    format (s, "trace_handle: 0x%x, len_not_first_buf: %d\n", b->trace_handle,
-	    b->total_length_not_including_first_buffer);
-  return s;
-}
-
-#define A(x) vec_add1(vm->pcap_buffer, (x))
-
-static void
-dispatch_pcap_trace (vlib_main_t * vm,
-		     vlib_node_runtime_t * node, vlib_frame_t * frame)
-{
-  int i;
-  vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **bufp, *b;
-  pcap_main_t *pm = &vlib_global_main.dispatch_pcap_main;
-  vlib_trace_main_t *tm = &vm->trace_main;
-  u32 capture_size;
-  vlib_node_t *n;
-  i32 n_left;
-  f64 time_now = vlib_time_now (vm);
-  u32 *from;
-  u8 *d;
-  u8 string_count;
-
-  /* Input nodes don't have frames yet */
-  if (frame == 0 || frame->n_vectors == 0)
-    return;
-
-  from = vlib_frame_vector_args (frame);
-  vlib_get_buffers (vm, from, bufs, frame->n_vectors);
-  bufp = bufs;
-
-  n = vlib_get_node (vm, node->node_index);
-
-  for (i = 0; i < frame->n_vectors; i++)
-    {
-      if (PREDICT_TRUE (pm->n_packets_captured < pm->n_packets_to_capture))
-	{
-	  b = bufp[i];
-
-	  vec_reset_length (vm->pcap_buffer);
-	  string_count = 0;
-
-	  /* Version, flags */
-	  A ((u8) VLIB_PCAP_MAJOR_VERSION);
-	  A ((u8) VLIB_PCAP_MINOR_VERSION);
-	  A (0 /* string_count */ );
-	  A (n->protocol_hint);
-
-	  /* Buffer index (big endian) */
-	  A ((from[i] >> 24) & 0xff);
-	  A ((from[i] >> 16) & 0xff);
-	  A ((from[i] >> 8) & 0xff);
-	  A ((from[i] >> 0) & 0xff);
-
-	  /* Node name, NULL-terminated ASCII */
-	  vm->pcap_buffer = format (vm->pcap_buffer, "%v%c", n->name, 0);
-	  string_count++;
-
-	  vm->pcap_buffer = format (vm->pcap_buffer, "%U%c",
-				    format_buffer_metadata, b, 0);
-	  string_count++;
-	  vm->pcap_buffer = format (vm->pcap_buffer, "%U%c",
-				    format_vnet_buffer_opaque, b, 0);
-	  string_count++;
-	  vm->pcap_buffer = format (vm->pcap_buffer, "%U%c",
-				    format_vnet_buffer_opaque2, b, 0);
-	  string_count++;
-
-	  /* Is this packet traced? */
-	  if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
-	    {
-	      vlib_trace_header_t **h
-		= pool_elt_at_index (tm->trace_buffer_pool,
-				     vlib_buffer_get_trace_index (b));
-
-	      vm->pcap_buffer = format (vm->pcap_buffer, "%U%c",
-					format_vlib_trace, vm, h[0], 0);
-	      string_count++;
-	    }
-
-	  /* Save the string count */
-	  vm->pcap_buffer[2] = string_count;
-
-	  /* Figure out how many bytes in the pcap trace */
-	  capture_size = vec_len (vm->pcap_buffer) +
-	    +vlib_buffer_length_in_chain (vm, b);
-
-	  clib_spinlock_lock_if_init (&pm->lock);
-	  n_left = clib_min (capture_size, 16384);
-	  d = pcap_add_packet (pm, time_now, n_left, capture_size);
-
-	  /* Copy the header */
-	  clib_memcpy_fast (d, vm->pcap_buffer, vec_len (vm->pcap_buffer));
-	  d += vec_len (vm->pcap_buffer);
-
-	  n_left = clib_min
-	    (vlib_buffer_length_in_chain (vm, b),
-	     (16384 - vec_len (vm->pcap_buffer)));
-	  /* Copy the packet data */
-	  while (1)
-	    {
-	      u32 copy_length = clib_min ((u32) n_left, b->current_length);
-	      clib_memcpy_fast (d, b->data + b->current_data, copy_length);
-	      n_left -= b->current_length;
-	      if (n_left <= 0)
-		break;
-	      d += b->current_length;
-	      ASSERT (b->flags & VLIB_BUFFER_NEXT_PRESENT);
-	      b = vlib_get_buffer (vm, b->next_buffer);
-	    }
-	  clib_spinlock_unlock_if_init (&pm->lock);
-	}
-    }
-}
-
 static_always_inline u64
 dispatch_node (vlib_main_t * vm,
 	       vlib_node_runtime_t * node,
@@ -1211,9 +1022,6 @@ dispatch_node (vlib_main_t * vm,
 	  vlib_buffer_t *b = vlib_get_buffer (vm, from[i]);
 	  add_trajectory_trace (b, node->node_index);
 	}
-      if (PREDICT_FALSE (vm->dispatch_pcap_enable))
-	dispatch_pcap_trace (vm, node, frame);
-
       if (PREDICT_TRUE (vm->dispatch_wrapper_fn == 0))
 	n = node->function (vm, node, frame);
       else
@@ -1221,9 +1029,6 @@ dispatch_node (vlib_main_t * vm,
     }
   else
     {
-      if (PREDICT_FALSE (vm->dispatch_pcap_enable))
-	dispatch_pcap_trace (vm, node, frame);
-
       if (PREDICT_TRUE (vm->dispatch_wrapper_fn == 0))
 	n = node->function (vm, node, frame);
       else
@@ -1713,19 +1518,6 @@ vl_api_send_pending_rpc_requests (vlib_main_t * vm)
 {
 }
 
-static inline void
-pcap_postmortem_reset (vlib_main_t * vm)
-{
-  pcap_main_t *pm = &vm->dispatch_pcap_main;
-
-  /* Reset the trace buffer and capture count */
-  clib_spinlock_lock_if_init (&pm->lock);
-  vec_reset_length (pm->pcap_data);
-  pm->n_packets_captured = 0;
-  clib_spinlock_unlock_if_init (&pm->lock);
-}
-
-
 static_always_inline void
 vlib_main_or_worker_loop (vlib_main_t * vm, int is_main)
 {
@@ -1821,17 +1613,6 @@ vlib_main_or_worker_loop (vlib_main_t * vm, int is_main)
 	clib_call_callbacks (vm->worker_thread_main_loop_callbacks, vm,
 			     cpu_time_now);
 
-      /*
-       * When trying to understand aggravating, hard-to-reproduce
-       * bugs: reset / restart the pcap dispatch trace once per
-       * main thread dispatch cycle. All threads share the same
-       * (spinlock-protected) dispatch trace buffer. It might take
-       * a few tries to capture a good post-mortem trace of
-       * a multi-thread issue. Best we can do without a big refactor job.
-       */
-      if (is_main && PREDICT_FALSE (vm->dispatch_pcap_postmortem != 0))
-	pcap_postmortem_reset (vm);
-
       /* Process pre-input nodes. */
       cpu_time_now = clib_cpu_time_now ();
       vec_foreach (n, nm->nodes_by_type[VLIB_NODE_TYPE_PRE_INPUT])
@@ -2013,6 +1794,44 @@ vlib_worker_loop (vlib_main_t * vm)
 
 vlib_main_t vlib_global_main;
 
+void
+vlib_add_del_post_mortem_callback (void *cb, int is_add)
+{
+  vlib_main_t *vm = &vlib_global_main;
+  int i;
+
+  if (is_add == 0)
+    {
+      for (i = vec_len (vm->post_mortem_callbacks) - 1; i >= 0; i--)
+	if (vm->post_mortem_callbacks[i] == cb)
+	  vec_del1 (vm->post_mortem_callbacks, i);
+      return;
+    }
+
+  for (i = 0; i < vec_len (vm->post_mortem_callbacks); i++)
+    if (vm->post_mortem_callbacks[i] == cb)
+      return;
+  vec_add1 (vm->post_mortem_callbacks, cb);
+}
+
+static void
+elog_post_mortem_dump (void)
+{
+  vlib_main_t *vm = &vlib_global_main;
+  elog_main_t *em = &vm->elog_main;
+
+  u8 *filename;
+  clib_error_t *error;
+
+  filename = format (0, "/tmp/elog_post_mortem.%d%c", getpid (), 0);
+  error = elog_write_file (em, (char *) filename, 1 /* flush ring */);
+  if (error)
+    clib_error_report (error);
+  /*
+   * We're in the middle of crashing. Don't try to free the filename.
+   */
+}
+
 static clib_error_t *
 vlib_main_configure (vlib_main_t * vm, unformat_input_t * input)
 {
@@ -2028,7 +1847,8 @@ vlib_main_configure (vlib_main_t * vm, unformat_input_t * input)
 	vm->configured_elog_ring_size =
 	  1 << max_log2 (vm->configured_elog_ring_size);
       else if (unformat (input, "elog-post-mortem-dump"))
-	vm->elog_post_mortem_dump = 1;
+	vlib_add_del_post_mortem_callback (elog_post_mortem_dump,
+					   /* is_add */ 1);
       else if (unformat (input, "buffer-alloc-success-rate %f",
 			 &vm->buffer_alloc_success_rate))
 	{
@@ -2267,292 +2087,6 @@ done:
   return 0;
 }
 
-int
-vlib_pcap_dispatch_trace_configure (vlib_pcap_dispatch_trace_args_t * a)
-{
-  vlib_main_t *vm = vlib_get_main ();
-  pcap_main_t *pm = &vm->dispatch_pcap_main;
-  vlib_trace_main_t *tm;
-  vlib_trace_node_t *tn;
-
-  if (a->status)
-    {
-      if (vm->dispatch_pcap_enable)
-	{
-	  int i;
-	  vlib_cli_output
-	    (vm, "pcap dispatch capture enabled: %d of %d pkts...",
-	     pm->n_packets_captured, pm->n_packets_to_capture);
-	  vlib_cli_output (vm, "capture to file %s", pm->file_name);
-
-	  for (i = 0; i < vec_len (vm->dispatch_buffer_trace_nodes); i++)
-	    {
-	      vlib_cli_output (vm,
-			       "Buffer trace of %d pkts from %U enabled...",
-			       a->buffer_traces_to_capture,
-			       format_vlib_node_name, vm,
-			       vm->dispatch_buffer_trace_nodes[i]);
-	    }
-	}
-      else
-	vlib_cli_output (vm, "pcap dispatch capture disabled");
-      return 0;
-    }
-
-  /* Consistency checks */
-
-  /* Enable w/ capture already enabled not allowed */
-  if (vm->dispatch_pcap_enable && a->enable)
-    return -7;			/* VNET_API_ERROR_INVALID_VALUE */
-
-  /* Disable capture with capture already disabled, not interesting */
-  if (vm->dispatch_pcap_enable == 0 && a->enable == 0)
-    return -81;			/* VNET_API_ERROR_VALUE_EXIST */
-
-  /* Change number of packets to capture while capturing */
-  if (vm->dispatch_pcap_enable && a->enable
-      && (pm->n_packets_to_capture != a->packets_to_capture))
-    return -8;			/* VNET_API_ERROR_INVALID_VALUE_2 */
-
-  /* Independent of enable/disable, to allow buffer trace multi nodes */
-  if (a->buffer_trace_node_index != ~0)
-    {
-      /* *INDENT-OFF* */
-      foreach_vlib_main ((
-        {
-          tm = &this_vlib_main->trace_main;
-          tm->verbose = 0;  /* not sure this ever did anything... */
-          vec_validate (tm->nodes, a->buffer_trace_node_index);
-          tn = tm->nodes + a->buffer_trace_node_index;
-          tn->limit += a->buffer_traces_to_capture;
-          if (a->post_mortem)
-            {
-              tm->filter_flag = FILTER_FLAG_POST_MORTEM;
-              tm->filter_count = ~0;
-            }
-          tm->trace_enable = 1;
-        }));
-      /* *INDENT-ON* */
-      vec_add1 (vm->dispatch_buffer_trace_nodes, a->buffer_trace_node_index);
-    }
-
-  if (a->enable)
-    {
-      /* Clean up from previous run, if any */
-      vec_free (pm->file_name);
-      vec_free (pm->pcap_data);
-      memset (pm, 0, sizeof (*pm));
-
-      vec_validate_aligned (vnet_trace_placeholder, 2048,
-			    CLIB_CACHE_LINE_BYTES);
-      if (pm->lock == 0)
-	clib_spinlock_init (&(pm->lock));
-
-      if (a->filename == 0)
-	a->filename = format (0, "/tmp/dispatch.pcap%c", 0);
-
-      pm->file_name = (char *) a->filename;
-      pm->n_packets_captured = 0;
-      pm->packet_type = PCAP_PACKET_TYPE_vpp;
-      pm->n_packets_to_capture = a->packets_to_capture;
-      vm->dispatch_pcap_postmortem = a->post_mortem;
-      /* *INDENT-OFF* */
-      foreach_vlib_main (({ this_vlib_main->dispatch_pcap_enable = 1;}));
-      /* *INDENT-ON* */
-    }
-  else
-    {
-      /* *INDENT-OFF* */
-      foreach_vlib_main ((
-        {
-          this_vlib_main->dispatch_pcap_enable = 0;
-          this_vlib_main->dispatch_pcap_postmortem = 0;
-          tm = &this_vlib_main->trace_main;
-          tm->filter_flag = 0;
-          tm->filter_count = 0;
-          tm->trace_enable = 0;
-        }));
-      /* *INDENT-ON* */
-      vec_reset_length (vm->dispatch_buffer_trace_nodes);
-      if (pm->n_packets_captured)
-	{
-	  clib_error_t *error;
-	  pm->n_packets_to_capture = pm->n_packets_captured;
-	  vlib_cli_output (vm, "Write %d packets to %s, and stop capture...",
-			   pm->n_packets_captured, pm->file_name);
-	  error = pcap_write (pm);
-	  if (pm->flags & PCAP_MAIN_INIT_DONE)
-	    pcap_close (pm);
-	  /* Report I/O errors... */
-	  if (error)
-	    {
-	      clib_error_report (error);
-	      return -11;	/* VNET_API_ERROR_SYSCALL_ERROR_1 */
-	    }
-	  return 0;
-	}
-      else
-	return -6;		/* VNET_API_ERROR_NO_SUCH_ENTRY */
-    }
-
-  return 0;
-}
-
-static clib_error_t *
-dispatch_trace_command_fn (vlib_main_t * vm,
-			   unformat_input_t * input, vlib_cli_command_t * cmd)
-{
-  unformat_input_t _line_input, *line_input = &_line_input;
-  vlib_pcap_dispatch_trace_args_t _a, *a = &_a;
-  u8 *filename = 0;
-  u32 max = 1000;
-  int rv;
-  int enable = 0;
-  int status = 0;
-  int post_mortem = 0;
-  u32 node_index = ~0, buffer_traces_to_capture = 100;
-
-  /* Get a line of input. */
-  if (!unformat_user (input, unformat_line_input, line_input))
-    return 0;
-
-  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
-    {
-      if (unformat (line_input, "on %=", &enable, 1))
-	;
-      else if (unformat (line_input, "enable %=", &enable, 1))
-	;
-      else if (unformat (line_input, "off %=", &enable, 0))
-	;
-      else if (unformat (line_input, "disable %=", &enable, 0))
-	;
-      else if (unformat (line_input, "max %d", &max))
-	;
-      else if (unformat (line_input, "packets-to-capture %d", &max))
-	;
-      else if (unformat (line_input, "file %U", unformat_vlib_tmpfile,
-			 &filename))
-	;
-      else if (unformat (line_input, "status %=", &status, 1))
-	;
-      else if (unformat (line_input, "buffer-trace %U %d",
-			 unformat_vlib_node, vm, &node_index,
-			 &buffer_traces_to_capture))
-	;
-      else if (unformat (line_input, "post-mortem %=", &post_mortem, 1))
-	;
-      else
-	{
-	  return clib_error_return (0, "unknown input `%U'",
-				    format_unformat_error, line_input);
-	}
-    }
-
-  unformat_free (line_input);
-
-  /* no need for memset (a, 0, sizeof (*a)), set all fields here. */
-  a->filename = filename;
-  a->enable = enable;
-  a->status = status;
-  a->packets_to_capture = max;
-  a->buffer_trace_node_index = node_index;
-  a->buffer_traces_to_capture = buffer_traces_to_capture;
-  a->post_mortem = post_mortem;
-
-  rv = vlib_pcap_dispatch_trace_configure (a);
-
-  switch (rv)
-    {
-    case 0:
-      break;
-
-    case -7:
-      return clib_error_return (0, "dispatch trace already enabled...");
-
-    case -81:
-      return clib_error_return (0, "dispatch trace already disabled...");
-
-    case -8:
-      return clib_error_return
-	(0, "can't change number of records to capture while tracing...");
-
-    case -11:
-      return clib_error_return (0, "I/O writing trace capture...");
-
-    case -6:
-      return clib_error_return (0, "No packets captured...");
-
-    default:
-      vlib_cli_output (vm, "WARNING: trace configure returned %d", rv);
-      break;
-    }
-  return 0;
-}
-
-/*?
- * This command is used to start or stop pcap dispatch trace capture, or show
- * the capture status.
- *
- * This command has the following optional parameters:
- *
- * - <b>on|off</b> - Used to start or stop capture.
- *
- * - <b>max <nn></b> - Depth of local buffer. Once '<em>nn</em>' number
- *   of packets have been received, buffer is flushed to file. Once another
- *   '<em>nn</em>' number of packets have been received, buffer is flushed
- *   to file, overwriting previous write. If not entered, value defaults
- *   to 100. Can only be updated if packet capture is off.
- *
- * - <b>file <name></b> - Used to specify the output filename. The file will
- *   be placed in the '<em>/tmp</em>' directory, so only the filename is
- *   supported. Directory should not be entered. If file already exists, file
- *   will be overwritten. If no filename is provided, '<em>/tmp/vpe.pcap</em>'
- *   will be used. Can only be updated if packet capture is off.
- *
- * - <b>status</b> - Displays the current status and configured attributes
- *   associated with a packet capture. If packet capture is in progress,
- *   '<em>status</em>' also will return the number of packets currently in
- *   the local buffer. All additional attributes entered on command line
- *   with '<em>status</em>' will be ignored and not applied.
- *
- * @cliexpar
- * Example of how to display the status of capture when off:
- * @cliexstart{pcap dispatch trace status}
- * max is 100, for any interface to file /tmp/vpe.pcap
- * pcap dispatch capture is off...
- * @cliexend
- * Example of how to start a dispatch trace capture:
- * @cliexstart{pcap dispatch trace on max 35 file dispatchTrace.pcap}
- * pcap dispatch capture on...
- * @cliexend
- * Example of how to start a dispatch trace capture with buffer tracing
- * @cliexstart{pcap dispatch trace on max 10000 file dispatchTrace.pcap buffer-trace dpdk-input 1000}
- * pcap dispatch capture on...
- * @cliexend
- * Example of how to display the status of a tx packet capture in progress:
- * @cliexstart{pcap tx trace status}
- * max is 35, dispatch trace to file /tmp/vppTest.pcap
- * pcap tx capture is on: 20 of 35 pkts...
- * @cliexend
- * Example of how to stop a tx packet capture:
- * @cliexstart{vppctl pcap dispatch trace off}
- * captured 21 pkts...
- * saved to /tmp/dispatchTrace.pcap...
- * Example of how to start a post-mortem dispatch trace:
- * pcap dispatch trace on max 20000 buffer-trace
- *     dpdk-input 3000000000 post-mortem
- * @cliexend
-?*/
-/* *INDENT-OFF* */
-VLIB_CLI_COMMAND (pcap_dispatch_trace_command, static) = {
-    .path = "pcap dispatch trace",
-    .short_help =
-    "pcap dispatch trace [on|off] [max <nn>] [file <name>] [status]\n"
-    "              [buffer-trace <input-node-name> <nn>][post-mortem]",
-    .function = dispatch_trace_command_fn,
-};
-/* *INDENT-ON* */
-
 vlib_main_t *
 vlib_get_main_not_inline (void)
 {
diff --git a/src/vlib/main.h b/src/vlib/main.h
index 3925989d841..3e3590abab0 100644
--- a/src/vlib/main.h
+++ b/src/vlib/main.h
@@ -47,7 +47,6 @@
 #include <vppinfra/pool.h>
 #include <vppinfra/random_buffer.h>
 #include <vppinfra/time.h>
-#include <vppinfra/pcap.h>
 
 #include <pthread.h>
 
@@ -180,13 +179,6 @@ typedef struct vlib_main_t
   /* Packet trace buffer. */
   vlib_trace_main_t trace_main;
 
-  /* Pcap dispatch trace main */
-  pcap_main_t dispatch_pcap_main;
-  uword dispatch_pcap_enable;
-  uword dispatch_pcap_postmortem;
-  u32 *dispatch_buffer_trace_nodes;
-  u8 *pcap_buffer;
-
   /* Packet trace capture filter */
   vlib_trace_filter_t trace_filter;
 
@@ -259,8 +251,8 @@ typedef struct vlib_main_t
   /* debugging */
   volatile int parked_at_barrier;
 
-  /* Attempt to do a post-mortem elog dump */
-  int elog_post_mortem_dump;
+  /* post-mortem callbacks */
+  void (**post_mortem_callbacks) (void);
 
   /*
    * Need to call vlib_worker_thread_node_runtime_update before
@@ -459,22 +451,8 @@ extern u8 **vlib_thread_stacks;
 u32 vlib_app_num_thread_stacks_needed (void) __attribute__ ((weak));
 
 extern void vlib_node_sync_stats (vlib_main_t * vm, vlib_node_t * n);
+void vlib_add_del_post_mortem_callback (void *cb, int is_add);
 
-#define VLIB_PCAP_MAJOR_VERSION 1
-#define VLIB_PCAP_MINOR_VERSION 0
-
-typedef struct
-{
-  u8 *filename;
-  int enable;
-  int status;
-  int post_mortem;
-  u32 packets_to_capture;
-  u32 buffer_trace_node_index;
-  u32 buffer_traces_to_capture;
-} vlib_pcap_dispatch_trace_args_t;
-
-int vlib_pcap_dispatch_trace_configure (vlib_pcap_dispatch_trace_args_t *);
 vlib_main_t *vlib_get_main_not_inline (void);
 elog_main_t *vlib_get_elog_main_not_inline ();
 
diff --git a/src/vlib/vlib.h b/src/vlib/vlib.h
index 8f0ea83569d..708732578f3 100644
--- a/src/vlib/vlib.h
+++ b/src/vlib/vlib.h
@@ -76,7 +76,6 @@ typedef u32 vlib_log_class_t;
 #include <vlib/trace_funcs.h>
 #include <vlib/global_funcs.h>
 #include <vlib/buffer_node.h>
-#include <vppinfra/pcap_funcs.h>
 
 #endif /* included_vlib_h */
 
diff --git a/src/vnet/buffer.h b/src/vnet/buffer.h
index bd70ea2722f..37db4130514 100644
--- a/src/vnet/buffer.h
+++ b/src/vnet/buffer.h
@@ -520,6 +520,9 @@ STATIC_ASSERT (sizeof (vnet_buffer_opaque2_t) <=
 
 format_function_t format_vnet_buffer;
 format_function_t format_vnet_buffer_offload;
+format_function_t format_vnet_buffer_flags;
+format_function_t format_vnet_buffer_opaque;
+format_function_t format_vnet_buffer_opaque2;
 
 static_always_inline void
 vnet_buffer_offload_flags_set (vlib_buffer_t *b, u32 oflags)
diff --git a/src/vnet/interface_funcs.h b/src/vnet/interface_funcs.h
index 186e0327884..565dcd5be99 100644
--- a/src/vnet/interface_funcs.h
+++ b/src/vnet/interface_funcs.h
@@ -510,6 +510,43 @@ u8 *format_vnet_interface_output_trace (u8 * s, va_list * va);
 serialize_function_t serialize_vnet_interface_state,
   unserialize_vnet_interface_state;
 
+/**
+ * @brief Add buffer (vlib_buffer_t) to the trace
+ *
+ * @param *pm - pcap_main_t
+ * @param *vm - vlib_main_t
+ * @param buffer_index - u32
+ * @param n_bytes_in_trace - u32
+ *
+ */
+static inline void
+pcap_add_buffer (pcap_main_t *pm, struct vlib_main_t *vm, u32 buffer_index,
+		 u32 n_bytes_in_trace)
+{
+  vlib_buffer_t *b = vlib_get_buffer (vm, buffer_index);
+  u32 n = vlib_buffer_length_in_chain (vm, b);
+  i32 n_left = clib_min (n_bytes_in_trace, n);
+  f64 time_now = vlib_time_now (vm);
+  void *d;
+
+  if (PREDICT_TRUE (pm->n_packets_captured < pm->n_packets_to_capture))
+    {
+      clib_spinlock_lock_if_init (&pm->lock);
+      d = pcap_add_packet (pm, time_now, n_left, n);
+      while (1)
+	{
+	  u32 copy_length = clib_min ((u32) n_left, b->current_length);
+	  clib_memcpy_fast (d, b->data + b->current_data, copy_length);
+	  n_left -= b->current_length;
+	  if (n_left <= 0)
+	    break;
+	  d += b->current_length;
+	  ASSERT (b->flags & VLIB_BUFFER_NEXT_PRESENT);
+	  b = vlib_get_buffer (vm, b->next_buffer);
+	}
+      clib_spinlock_unlock_if_init (&pm->lock);
+    }
+}
 #endif /* included_vnet_interface_funcs_h */
 
 /*
diff --git a/src/vnet/vnet.h b/src/vnet/vnet.h
index 38777b9b24f..1deaff66375 100644
--- a/src/vnet/vnet.h
+++ b/src/vnet/vnet.h
@@ -112,6 +112,7 @@ typedef struct vnet_main_t
 
 extern vnet_main_t vnet_main;
 
+#include <vppinfra/pcap_funcs.h>
 #include <vnet/interface_funcs.h>
 #include <vnet/global_funcs.h>
 
diff --git a/src/vppinfra/pcap_funcs.h b/src/vppinfra/pcap_funcs.h
index 125c3bd2517..2c51ab72383 100644
--- a/src/vppinfra/pcap_funcs.h
+++ b/src/vppinfra/pcap_funcs.h
@@ -54,45 +54,6 @@ pcap_add_packet (pcap_main_t * pm,
   return h->data;
 }
 
-/**
- * @brief Add buffer (vlib_buffer_t) to the trace
- *
- * @param *pm - pcap_main_t
- * @param *vm - vlib_main_t
- * @param buffer_index - u32
- * @param n_bytes_in_trace - u32
- *
- */
-static inline void
-pcap_add_buffer (pcap_main_t * pm,
-		 struct vlib_main_t *vm, u32 buffer_index,
-		 u32 n_bytes_in_trace)
-{
-  vlib_buffer_t *b = vlib_get_buffer (vm, buffer_index);
-  u32 n = vlib_buffer_length_in_chain (vm, b);
-  i32 n_left = clib_min (n_bytes_in_trace, n);
-  f64 time_now = vlib_time_now (vm);
-  void *d;
-
-  if (PREDICT_TRUE (pm->n_packets_captured < pm->n_packets_to_capture))
-    {
-      clib_spinlock_lock_if_init (&pm->lock);
-      d = pcap_add_packet (pm, time_now, n_left, n);
-      while (1)
-	{
-	  u32 copy_length = clib_min ((u32) n_left, b->current_length);
-	  clib_memcpy_fast (d, b->data + b->current_data, copy_length);
-	  n_left -= b->current_length;
-	  if (n_left <= 0)
-	    break;
-	  d += b->current_length;
-	  ASSERT (b->flags & VLIB_BUFFER_NEXT_PRESENT);
-	  b = vlib_get_buffer (vm, b->next_buffer);
-	}
-      clib_spinlock_unlock_if_init (&pm->lock);
-    }
-}
-
 #endif /* included_vppinfra_pcap_funcs_h */
 
 /*