dispatch-trace: move dispatch trace pcap code to plugin

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

2 files changed, 523 insertions, 0 deletions

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",
+};