pcap-based dispatch tracer

To facilitate dispatch trajectory tracing, vlib_buffer_t decoding, etc.
through Wireshark

Change-Id: I31356b9fa1f40cba8830aaf10a86a9fbb7546438
Signed-off-by: Dave Barach <dave@barachs.net>

18 files changed, 469 insertions, 93 deletions

diff --git a/src/plugins/cdp/cdp_periodic.c b/src/plugins/cdp/cdp_periodic.c
index da08523176f..b0b33cf9d41 100644
--- a/src/plugins/cdp/cdp_periodic.c
+++ b/src/plugins/cdp/cdp_periodic.c
@@ -14,7 +14,7 @@
  */
 #include <cdp/cdp.h>
 #include <vppinfra/hash.h>
-#include <vnet/unix/pcap.h>
+#include <vppinfra/pcap.h>
 #include <vnet/srp/srp.h>
 #include <vnet/ppp/ppp.h>
 #include <vnet/hdlc/hdlc.h>
diff --git a/src/plugins/dpdk/device/dpdk.h b/src/plugins/dpdk/device/dpdk.h
index 007a7b91905..0e5851dcbc6 100644
--- a/src/plugins/dpdk/device/dpdk.h
+++ b/src/plugins/dpdk/device/dpdk.h
@@ -44,7 +44,7 @@
 #include <rte_bus_pci.h>
 #include <rte_flow.h>
 
-#include <vnet/unix/pcap.h>
+#include <vppinfra/pcap.h>
 #include <vnet/devices/devices.h>
 
 #if CLIB_DEBUG > 0
diff --git a/src/vlib/main.c b/src/vlib/main.c
index 964feb06c65..666b869915f 100644
--- a/src/vlib/main.c
+++ b/src/vlib/main.c
@@ -944,6 +944,84 @@ add_trajectory_trace (vlib_buffer_t * b, u32 node_index)
 #endif
 }
 
+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;
+  u8 name_tlv[64];
+  pcap_main_t *pm = &vm->dispatch_pcap_main;
+  u32 capture_size;
+  vlib_node_t *n;
+  i32 n_left;
+  f64 time_now = vlib_time_now (vm);
+  u32 *from;
+  u32 name_length;
+  u8 *d;
+
+  /* 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;
+
+  /* Create a node name TLV, since WS can't possibly guess */
+  n = vlib_get_node (vm, node->node_index);
+  name_length = vec_len (n->name);
+  name_length = name_length < ARRAY_LEN (name_tlv) - 2 ?
+    name_length : ARRAY_LEN (name_tlv) - 2;
+
+  name_tlv[0] = (u8) name_length;
+  clib_memcpy_fast (name_tlv + 1, n->name, name_length);
+  name_tlv[name_length + 1] = 0;
+
+  for (i = 0; i < frame->n_vectors; i++)
+    {
+      if (PREDICT_TRUE (pm->n_packets_captured < pm->n_packets_to_capture))
+	{
+	  b = bufp[i];
+
+	  /* Figure out how many bytes we're capturing */
+	  capture_size = (sizeof (vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE) + vlib_buffer_length_in_chain (vm, b) + sizeof (u32) + +(name_length + 2);	/* +2: count plus NULL byte */
+
+	  clib_spinlock_lock_if_init (&pm->lock);
+	  n_left = clib_min (capture_size, 512);
+	  d = pcap_add_packet (pm, time_now, n_left, capture_size);
+
+	  /* Copy the buffer index */
+	  clib_memcpy_fast (d, &from[i], sizeof (u32));
+	  d += 4;
+
+	  /* Copy the name TLV */
+	  clib_memcpy_fast (d, name_tlv, name_length + 2);
+	  d += name_length + 2;
+
+	  /* Copy the buffer metadata, but not the rewrite space */
+	  clib_memcpy_fast (d, b, sizeof (*b) - VLIB_BUFFER_PRE_DATA_SIZE);
+	  d += sizeof (*b) - VLIB_BUFFER_PRE_DATA_SIZE;
+
+	  n_left = clib_min (vlib_buffer_length_in_chain (vm, b),
+			     512 - (sizeof (*b) - VLIB_BUFFER_PRE_DATA_SIZE));
+	  /* 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,
@@ -1020,10 +1098,16 @@ 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);
 	  n = node->function (vm, node, frame);
 	}
       else
-	n = node->function (vm, node, frame);
+	{
+	  if (PREDICT_FALSE (vm->dispatch_pcap_enable))
+	    dispatch_pcap_trace (vm, node, frame);
+	  n = node->function (vm, node, frame);
+	}
 
       t = clib_cpu_time_now ();
 
@@ -1891,6 +1975,226 @@ done:
   return 0;
 }
 
+static inline clib_error_t *
+pcap_dispatch_trace_command_internal (vlib_main_t * vm,
+				      unformat_input_t * input,
+				      vlib_cli_command_t * cmd, int rx_tx)
+{
+#define PCAP_DEF_PKT_TO_CAPTURE (100)
+
+  unformat_input_t _line_input, *line_input = &_line_input;
+  pcap_main_t *pm = &vm->dispatch_pcap_main;
+  u8 *filename;
+  u8 *chroot_filename = 0;
+  u32 max = 0;
+  int enabled = 0;
+  int errorFlag = 0;
+  clib_error_t *error = 0;
+
+  /* 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"))
+	{
+	  if (vm->dispatch_pcap_enable == 0)
+	    {
+	      enabled = 1;
+	    }
+	  else
+	    {
+	      vlib_cli_output (vm, "pcap dispatch capture already on...");
+	      errorFlag = 1;
+	      break;
+	    }
+	}
+      else if (unformat (line_input, "off"))
+	{
+	  if (vm->dispatch_pcap_enable)
+	    {
+	      vlib_cli_output
+		(vm, "captured %d pkts...", pm->n_packets_captured);
+	      if (pm->n_packets_captured)
+		{
+		  pm->n_packets_to_capture = pm->n_packets_captured;
+		  error = pcap_write (pm);
+		  if (error)
+		    clib_error_report (error);
+		  else
+		    vlib_cli_output (vm, "saved to %s...", pm->file_name);
+		}
+	      vm->dispatch_pcap_enable = 0;
+	    }
+	  else
+	    {
+	      vlib_cli_output (vm, "pcap tx capture already off...");
+	      errorFlag = 1;
+	      break;
+	    }
+	}
+      else if (unformat (line_input, "max %d", &max))
+	{
+	  if (vm->dispatch_pcap_enable)
+	    {
+	      vlib_cli_output
+		(vm,
+		 "can't change max value while pcap tx capture active...");
+	      errorFlag = 1;
+	      break;
+	    }
+	  pm->n_packets_to_capture = max;
+	}
+      else if (unformat (line_input, "file %s", &filename))
+	{
+	  if (vm->dispatch_pcap_enable)
+	    {
+	      vlib_cli_output
+		(vm, "can't change file while pcap tx capture active...");
+	      errorFlag = 1;
+	      break;
+	    }
+
+	  /* Brain-police user path input */
+	  if (strstr ((char *) filename, "..")
+	      || index ((char *) filename, '/'))
+	    {
+	      vlib_cli_output (vm, "illegal characters in filename '%s'",
+			       filename);
+	      vlib_cli_output (vm, "Hint: .. and / are not allowed.");
+	      vec_free (filename);
+	      errorFlag = 1;
+	      break;
+	    }
+
+	  chroot_filename = format (0, "/tmp/%s%c", filename, 0);
+	  vec_free (filename);
+	}
+      else if (unformat (line_input, "status"))
+	{
+	  if (vm->dispatch_pcap_enable)
+	    {
+	      vlib_cli_output
+		(vm, "pcap dispatch capture is on: %d of %d pkts...",
+		 pm->n_packets_captured, pm->n_packets_to_capture);
+	      vlib_cli_output (vm, "Capture to file %s", pm->file_name);
+	    }
+	  else
+	    {
+	      vlib_cli_output (vm, "pcap dispatch capture is off...");
+	    }
+	  break;
+	}
+
+      else
+	{
+	  error = clib_error_return (0, "unknown input `%U'",
+				     format_unformat_error, line_input);
+	  errorFlag = 1;
+	  break;
+	}
+    }
+  unformat_free (line_input);
+
+
+  if (errorFlag == 0)
+    {
+      /* Since no error, save configured values. */
+      if (chroot_filename)
+	{
+	  if (pm->file_name)
+	    vec_free (pm->file_name);
+	  vec_add1 (chroot_filename, 0);
+	  pm->file_name = (char *) chroot_filename;
+	}
+
+      if (max)
+	pm->n_packets_to_capture = max;
+
+      if (enabled)
+	{
+	  if (pm->file_name == 0)
+	    pm->file_name = (char *) format (0, "/tmp/dispatch.pcap%c", 0);
+
+	  pm->n_packets_captured = 0;
+	  pm->packet_type = PCAP_PACKET_TYPE_user13;
+	  if (pm->lock == 0)
+	    clib_spinlock_init (&(pm->lock));
+	  vm->dispatch_pcap_enable = 1;
+	  vlib_cli_output (vm, "pcap dispatch capture on...");
+	}
+    }
+  else if (chroot_filename)
+    vec_free (chroot_filename);
+
+  return error;
+}
+
+static clib_error_t *
+pcap_dispatch_trace_command_fn (vlib_main_t * vm,
+				unformat_input_t * input,
+				vlib_cli_command_t * cmd)
+{
+  return pcap_dispatch_trace_command_internal (vm, input, cmd, VLIB_RX);
+}
+
+/*?
+ * 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 dispatc 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...
+ * @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]",
+    .function = pcap_dispatch_trace_command_fn,
+};
+/* *INDENT-ON* */
+
 /*
  * fd.io coding-style-patch-verification: ON
  *
diff --git a/src/vlib/main.h b/src/vlib/main.h
index 1cf8fe188b1..9e7538e9f00 100644
--- a/src/vlib/main.h
+++ b/src/vlib/main.h
@@ -47,6 +47,7 @@
 #include <vppinfra/random_buffer.h>
 #include <vppinfra/time.h>
 #include <vppinfra/pmc.h>
+#include <vppinfra/pcap.h>
 
 #include <pthread.h>
 
@@ -130,6 +131,10 @@ 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;
+
   /* Error handling. */
   vlib_error_main_t error_main;
 
diff --git a/src/vlib/vlib.h b/src/vlib/vlib.h
index ba72f46aab2..49bb51bfbe3 100644
--- a/src/vlib/vlib.h
+++ b/src/vlib/vlib.h
@@ -73,8 +73,8 @@ struct vlib_main_t;
 #include <vlib/node_funcs.h>
 #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/CMakeLists.txt b/src/vnet/CMakeLists.txt
index d7aa4a5a951..ac448e268b6 100644
--- a/src/vnet/CMakeLists.txt
+++ b/src/vnet/CMakeLists.txt
@@ -1143,14 +1143,12 @@ list(APPEND VNET_API_FILES feature/feature.api)
 
 list(APPEND VNET_SOURCES
   unix/gdb_funcs.c
-  unix/pcap.c
   unix/tap_api.c
   unix/tapcli.c
   unix/tuntap.c
 )
 
 list(APPEND VNET_HEADERS
-  unix/pcap.h
   unix/tuntap.h
   unix/tapcli.h
 )
diff --git a/src/vnet/devices/devices.h b/src/vnet/devices/devices.h
index cc960c98f23..d561563c295 100644
--- a/src/vnet/devices/devices.h
+++ b/src/vnet/devices/devices.h
@@ -16,7 +16,7 @@
 #ifndef included_vnet_vnet_device_h
 #define included_vnet_vnet_device_h
 
-#include <vnet/unix/pcap.h>
+#include <vppinfra/pcap.h>
 #include <vnet/l3_types.h>
 
 typedef enum
diff --git a/src/vnet/flow/flow.h b/src/vnet/flow/flow.h
index 19b6761474d..51cef7674a6 100644
--- a/src/vnet/flow/flow.h
+++ b/src/vnet/flow/flow.h
@@ -17,7 +17,7 @@
 #define included_vnet_flow_flow_h
 
 #include <vppinfra/clib.h>
-#include <vnet/unix/pcap.h>
+#include <vppinfra/pcap.h>
 #include <vnet/l3_types.h>
 #include <vnet/ip/ip4_packet.h>
 #include <vnet/ip/ip6_packet.h>
diff --git a/src/vnet/interface.h b/src/vnet/interface.h
index 061bd2ce4fa..f6f486e4591 100644
--- a/src/vnet/interface.h
+++ b/src/vnet/interface.h
@@ -40,7 +40,8 @@
 #ifndef included_vnet_interface_h
 #define included_vnet_interface_h
 
-#include <vnet/unix/pcap.h>
+#include <vlib/vlib.h>
+#include <vppinfra/pcap.h>
 #include <vnet/l3_types.h>
 
 struct vnet_main_t;
diff --git a/src/vnet/pg/cli.c b/src/vnet/pg/cli.c
index 13b0e97cf4c..8b543d3ca38 100644
--- a/src/vnet/pg/cli.c
+++ b/src/vnet/pg/cli.c
@@ -43,7 +43,7 @@
 #include <vnet/pg/pg.h>
 
 #ifdef CLIB_UNIX
-#include <vnet/unix/pcap.h>
+#include <vppinfra/pcap.h>
 #endif
 
 /* Root of all packet generator cli commands. */
diff --git a/src/vnet/pg/pg.h b/src/vnet/pg/pg.h
index ab3ae44aed6..99652b43981 100644
--- a/src/vnet/pg/pg.h
+++ b/src/vnet/pg/pg.h
@@ -43,7 +43,7 @@
 #include <vlib/vlib.h>		/* for VLIB_N_RX_TX */
 #include <vnet/pg/edit.h>
 #include <vppinfra/fifo.h>	/* for buffer_fifo */
-#include <vnet/unix/pcap.h>
+#include <vppinfra/pcap.h>
 #include <vnet/interface.h>
 
 extern vnet_device_class_t pg_dev_class;
diff --git a/src/vnet/unix/pcap2cinit.c b/src/vnet/unix/pcap2cinit.c
index a81722e4062..5c159ebd555 100644
--- a/src/vnet/unix/pcap2cinit.c
+++ b/src/vnet/unix/pcap2cinit.c
@@ -19,7 +19,7 @@
  * @brief Functions to convert PCAP file format to a u8 ** initializer
  *
  */
-#include <vnet/unix/pcap.h>
+#include <vppinfra/pcap.h>
 #include <vnet/ethernet/packet.h>
 #include <stdio.h>
 
diff --git a/src/vnet/unix/pcap2pg.c b/src/vnet/unix/pcap2pg.c
index 712907a5bac..e27dad7a412 100644
--- a/src/vnet/unix/pcap2pg.c
+++ b/src/vnet/unix/pcap2pg.c
@@ -19,7 +19,7 @@
  * @brief Functions to convert PCAP file format to VPP PG (Packet Generator)
  *
  */
-#include <vnet/unix/pcap.h>
+#include <vppinfra/pcap.h>
 #include <vnet/ethernet/packet.h>
 #include <stdio.h>
 
diff --git a/src/vnet/vnet.h b/src/vnet/vnet.h
index 5098aa6ecec..9b2a8788752 100644
--- a/src/vnet/vnet.h
+++ b/src/vnet/vnet.h
@@ -42,7 +42,7 @@
 
 #include <vppinfra/types.h>
 
-#include <vnet/unix/pcap.h>
+#include <vppinfra/pcap.h>
 #include <vnet/buffer.h>
 #include <vnet/config.h>
 #include <vnet/interface.h>
diff --git a/src/vppinfra/CMakeLists.txt b/src/vppinfra/CMakeLists.txt
index 6e1a4fd861a..4f0d16bd568 100644
--- a/src/vppinfra/CMakeLists.txt
+++ b/src/vppinfra/CMakeLists.txt
@@ -56,6 +56,7 @@ set(VPPINFRA_SRCS
   macros.c
   maplog.c
   mhash.c
+  pcap.c
   pmalloc.c
   pool.c
   ptclosure.c
@@ -135,6 +136,8 @@ set(VPPINFRA_HEADERS
   mheap_bootstrap.h
   mheap.h
   os.h
+  pcap.h
+  pcap_funcs.h
   pipeline.h
   pmalloc.h
   pool.h
diff --git a/src/vnet/unix/pcap.c b/src/vppinfra/pcap.c
index 3c9ce314d9c..8f644e30f1d 100644
--- a/src/vnet/unix/pcap.c
+++ b/src/vppinfra/pcap.c
@@ -37,8 +37,8 @@
  *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-#include <vnet/unix/pcap.h>
 #include <sys/fcntl.h>
+#include <vppinfra/pcap.h>
 
 /**
  * @file
@@ -47,7 +47,7 @@
  * Usage:
  *
  * <code><pre>
- * \#include <vnet/unix/pcap.h>
+ * \#include <vppinfra/pcap.h>
  *
  * static pcap_main_t pcap = {
  *  .file_name = "/tmp/ip4",
diff --git a/src/vnet/unix/pcap.h b/src/vppinfra/pcap.h
index 0706aace496..5889a793401 100644
--- a/src/vnet/unix/pcap.h
+++ b/src/vppinfra/pcap.h
@@ -40,26 +40,63 @@
  * @file
  * @brief PCAP utility definitions
  */
-#ifndef included_vnet_pcap_h
-#define included_vnet_pcap_h
+#ifndef included_vppinfra_pcap_h
+#define included_vppinfra_pcap_h
 
-#include <vlib/vlib.h>
+#include <vppinfra/types.h>
+#include <vppinfra/cache.h>
+#include <vppinfra/mem.h>
+#include <vppinfra/lock.h>
 
 /**
  * @brief Packet types supported by PCAP
  *
+ * These codes end up in the pcap file header.
+ * If you decide to build a wireshark dissector,
+ * you'll need to know that these codes are mapped
+ * through the pcap_to_wtap_map[] array in .../wiretap/pcap-common.c.
+ *
+ * For example:
+ *
+ *   { 160,		WTAP_ENCAP_USER13 },
+ *
+ * A file with (vpp) packet type PCAP_PACKET_TYPE_user13
+ * aka 160, will need a top-level dissector registered to
+ * deal with WTAP_ENCAP_USER13 [=58].
+ *
+ * Something like so:
+ *
+ * dissector_add_uint("wtap_encap", WTAP_ENCAP_USER13, vpp_dissector_handle);
+ *
  * null 0
  * ethernet 1
  * ppp 9
  * ip 12
  * hdlc 104
+ * user0 147 ... user15 162
  */
 #define foreach_vnet_pcap_packet_type           \
   _ (null, 0)					\
   _ (ethernet, 1)				\
   _ (ppp, 9)					\
   _ (ip, 12)					\
-  _ (hdlc, 104)
+  _ (hdlc, 104)                                 \
+  _ (user0,    147)                             \
+  _ (user1,    148)                             \
+  _ (user2,    149)                             \
+  _ (user3,    150)                             \
+  _ (user4,    151)                             \
+  _ (user5,    152)                             \
+  _ (user6,    153)                             \
+  _ (user7,    154)                             \
+  _ (user8,    155)                             \
+  _ (user9,    156)                             \
+  _ (user10,   157)                             \
+  _ (user11,   158)                             \
+  _ (user12,   159)                             \
+  _ (user13,   160)                             \
+  _ (user14,   161)                             \
+  _ (user15,   162)
 
 typedef enum
 {
@@ -161,79 +198,7 @@ typedef struct
   u32 min_packet_bytes, max_packet_bytes;
 } pcap_main_t;
 
-/** Write out data to output file. */
-clib_error_t *pcap_write (pcap_main_t * pm);
-
-/** Read data from file. */
-clib_error_t *pcap_read (pcap_main_t * pm);
-
-/**
- * @brief Add packet
- *
- * @param *pm - pcap_main_t
- * @param time_now - f64
- * @param n_bytes_in_trace - u32
- * @param n_bytes_in_packet - u32
- *
- * @return Packet Data
- *
- */
-static inline void *
-pcap_add_packet (pcap_main_t * pm,
-		 f64 time_now, u32 n_bytes_in_trace, u32 n_bytes_in_packet)
-{
-  pcap_packet_header_t *h;
-  u8 *d;
-
-  vec_add2 (pm->pcap_data, d, sizeof (h[0]) + n_bytes_in_trace);
-  h = (void *) (d);
-  h->time_in_sec = time_now;
-  h->time_in_usec = 1e6 * (time_now - h->time_in_sec);
-  h->n_packet_bytes_stored_in_file = n_bytes_in_trace;
-  h->n_bytes_in_packet = n_bytes_in_packet;
-  pm->n_packets_captured++;
-  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,
-		 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_pcap_h */
+#endif /* included_vppinfra_pcap_h */
 
 /*
  * fd.io coding-style-patch-verification: ON
diff --git a/src/vppinfra/pcap_funcs.h b/src/vppinfra/pcap_funcs.h
new file mode 100644
index 00000000000..364f4be2333
--- /dev/null
+++ b/src/vppinfra/pcap_funcs.h
@@ -0,0 +1,100 @@
+/*
+ * 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.
+ */
+
+#ifndef included_vppinfra_pcap_funcs_h
+#define included_vppinfra_pcap_funcs_h
+
+/** Write out data to output file. */
+clib_error_t *pcap_write (pcap_main_t * pm);
+
+/** Read data from file. */
+clib_error_t *pcap_read (pcap_main_t * pm);
+
+/**
+ * @brief Add packet
+ *
+ * @param *pm - pcap_main_t
+ * @param time_now - f64
+ * @param n_bytes_in_trace - u32
+ * @param n_bytes_in_packet - u32
+ *
+ * @return Packet Data
+ *
+ */
+static inline void *
+pcap_add_packet (pcap_main_t * pm,
+		 f64 time_now, u32 n_bytes_in_trace, u32 n_bytes_in_packet)
+{
+  pcap_packet_header_t *h;
+  u8 *d;
+
+  vec_add2 (pm->pcap_data, d, sizeof (h[0]) + n_bytes_in_trace);
+  h = (void *) (d);
+  h->time_in_sec = time_now;
+  h->time_in_usec = 1e6 * (time_now - h->time_in_sec);
+  h->n_packet_bytes_stored_in_file = n_bytes_in_trace;
+  h->n_bytes_in_packet = n_bytes_in_packet;
+  pm->n_packets_captured++;
+  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 */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */