2 * Copyright (c) 2015 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 * trace.c: VLIB trace buffer.
18 * Copyright (c) 2008 Eliot Dresselhaus
20 * Permission is hereby granted, free of charge, to any person obtaining
21 * a copy of this software and associated documentation files (the
22 * "Software"), to deal in the Software without restriction, including
23 * without limitation the rights to use, copy, modify, merge, publish,
24 * distribute, sublicense, and/or sell copies of the Software, and to
25 * permit persons to whom the Software is furnished to do so, subject to
26 * the following conditions:
28 * The above copyright notice and this permission notice shall be
29 * included in all copies or substantial portions of the Software.
31 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
32 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
33 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
34 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
35 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
36 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
37 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
40 #include <vlib/vlib.h>
41 #include <vlib/threads.h>
43 u8 *vnet_trace_placeholder;
45 /* Helper function for nodes which only trace buffer data. */
47 vlib_trace_frame_buffers_only (vlib_main_t * vm,
48 vlib_node_runtime_t * node,
51 uword next_buffer_stride,
52 uword n_buffer_data_bytes_in_trace)
62 vlib_buffer_t *b0, *b1;
65 /* Prefetch next iteration. */
66 vlib_prefetch_buffer_with_index (vm, from[2], LOAD);
67 vlib_prefetch_buffer_with_index (vm, from[3], LOAD);
72 b0 = vlib_get_buffer (vm, bi0);
73 b1 = vlib_get_buffer (vm, bi1);
75 if (b0->flags & VLIB_BUFFER_IS_TRACED)
77 t0 = vlib_add_trace (vm, node, b0, n_buffer_data_bytes_in_trace);
78 clib_memcpy_fast (t0, b0->data + b0->current_data,
79 n_buffer_data_bytes_in_trace);
81 if (b1->flags & VLIB_BUFFER_IS_TRACED)
83 t1 = vlib_add_trace (vm, node, b1, n_buffer_data_bytes_in_trace);
84 clib_memcpy_fast (t1, b1->data + b1->current_data,
85 n_buffer_data_bytes_in_trace);
99 b0 = vlib_get_buffer (vm, bi0);
101 if (b0->flags & VLIB_BUFFER_IS_TRACED)
103 t0 = vlib_add_trace (vm, node, b0, n_buffer_data_bytes_in_trace);
104 clib_memcpy_fast (t0, b0->data + b0->current_data,
105 n_buffer_data_bytes_in_trace);
112 /* Free up all trace buffer memory. */
114 clear_trace_buffer (void)
117 vlib_trace_main_t *tm;
122 tm = &this_vlib_main->trace_main;
124 tm->trace_enable = 0;
125 vec_free (tm->nodes);
130 tm = &this_vlib_main->trace_main;
132 for (i = 0; i < vec_len (tm->trace_buffer_pool); i++)
133 if (! pool_is_free_index (tm->trace_buffer_pool, i))
134 vec_free (tm->trace_buffer_pool[i]);
135 pool_free (tm->trace_buffer_pool);
141 format_vlib_trace (u8 * s, va_list * va)
143 vlib_main_t *vm = va_arg (*va, vlib_main_t *);
144 vlib_trace_header_t *h = va_arg (*va, vlib_trace_header_t *);
145 vlib_trace_header_t *e = vec_end (h);
146 vlib_node_t *node, *prev_node;
147 clib_time_t *ct = &vm->clib_time;
153 node = vlib_get_node (vm, h->node_index);
155 if (node != prev_node)
158 (h->time - vm->cpu_time_main_loop_start) * ct->seconds_per_clock;
160 format (s, "\n%U: %v", format_time_interval, "h:m:s:u", t,
165 if (node->format_trace)
166 s = format (s, "\n %U", node->format_trace, vm, node, h->data);
168 s = format (s, "\n %U", node->format_buffer, h->data);
170 h = vlib_trace_header_next (h);
176 /* Root of all trace cli commands. */
178 VLIB_CLI_COMMAND (trace_cli_command,static) = {
180 .short_help = "Packet tracer commands",
185 trace_time_cmp (void *a1, void *a2)
187 vlib_trace_header_t **t1 = a1;
188 vlib_trace_header_t **t2 = a2;
189 i64 dt = t1[0]->time - t2[0]->time;
190 return dt < 0 ? -1 : (dt > 0 ? +1 : 0);
194 * Return 1 if this packet passes the trace filter, or 0 otherwise
197 filter_accept (vlib_trace_main_t * tm, vlib_trace_header_t * h)
199 vlib_trace_header_t *e = vec_end (h);
201 if (tm->filter_flag == 0)
205 * When capturing a post-mortem dispatch trace,
206 * toss all existing traces once per dispatch cycle.
207 * So we can trace 4 billion pkts without running out of
210 if (tm->filter_flag == FILTER_FLAG_POST_MORTEM)
213 if (tm->filter_flag == FILTER_FLAG_INCLUDE)
217 if (h->node_index == tm->filter_node_index)
219 h = vlib_trace_header_next (h);
223 else /* FILTER_FLAG_EXCLUDE */
227 if (h->node_index == tm->filter_node_index)
229 h = vlib_trace_header_next (h);
238 * Remove traces from the trace buffer pool that don't pass the filter
241 trace_apply_filter (vlib_main_t * vm)
243 vlib_trace_main_t *tm = &vm->trace_main;
244 vlib_trace_header_t **h;
245 vlib_trace_header_t ***traces_to_remove = 0;
252 if (tm->filter_flag == FILTER_FLAG_NONE)
256 * Ideally we would retain the first N traces that pass the filter instead
261 pool_foreach (h, tm->trace_buffer_pool,
263 accept = filter_accept(tm, h[0]);
265 if ((n_accepted == tm->filter_count) || !accept)
266 vec_add1 (traces_to_remove, h);
272 /* remove all traces that we don't want to keep */
273 for (index = 0; index < vec_len (traces_to_remove); index++)
275 trace_index = traces_to_remove[index] - tm->trace_buffer_pool;
276 _vec_len (tm->trace_buffer_pool[trace_index]) = 0;
277 pool_put_index (tm->trace_buffer_pool, trace_index);
280 vec_free (traces_to_remove);
283 static clib_error_t *
284 cli_show_trace_buffer (vlib_main_t * vm,
285 unformat_input_t * input, vlib_cli_command_t * cmd)
287 vlib_trace_main_t *tm;
288 vlib_trace_header_t **h, **traces;
295 * By default display only this many traces. To display more, explicitly
296 * specify a max. This prevents unexpectedly huge outputs.
299 while (unformat_check_input (input) != (uword) UNFORMAT_END_OF_INPUT)
301 if (unformat (input, "max %d", &max))
304 return clib_error_create ("expected 'max COUNT', got `%U'",
305 format_unformat_error, input);
309 /* Get active traces from pool. */
314 fmt = "------------------- Start of thread %d %s -------------------\n";
315 s = format (s, fmt, index, vlib_worker_threads[index].name);
317 tm = &this_vlib_main->trace_main;
319 trace_apply_filter(this_vlib_main);
322 pool_foreach (h, tm->trace_buffer_pool,
324 vec_add1 (traces, h[0]);
327 if (vec_len (traces) == 0)
329 s = format (s, "No packets in trace buffer\n");
333 /* Sort them by increasing time. */
334 vec_sort_with_function (traces, trace_time_cmp);
336 for (i = 0; i < vec_len (traces); i++)
340 vlib_cli_output (vm, "Limiting display to %d packets."
341 " To display more specify max.", max);
345 s = format (s, "Packet %d\n%U\n\n", i + 1,
346 format_vlib_trace, vm, traces[i]);
356 vlib_cli_output (vm, "%v", s);
362 VLIB_CLI_COMMAND (show_trace_cli,static) = {
363 .path = "show trace",
364 .short_help = "Show trace buffer [max COUNT]",
365 .function = cli_show_trace_buffer,
369 int vlib_enable_disable_pkt_trace_filter (int enable) __attribute__ ((weak));
372 vlib_enable_disable_pkt_trace_filter (int enable)
378 vlib_trace_stop_and_clear (void)
380 vlib_enable_disable_pkt_trace_filter (0); /* disble tracing */
381 clear_trace_buffer ();
386 trace_update_capture_options (u32 add, u32 node_index, u32 filter, u8 verbose)
388 vlib_trace_main_t *tm;
389 vlib_trace_node_t *tn;
397 tm = &this_vlib_main->trace_main;
398 tm->verbose = verbose;
399 vec_validate (tm->nodes, node_index);
400 tn = tm->nodes + node_index;
403 * Adding 0 makes no real sense, and there wa no other way
404 * to explicilty zero-out the limits and count, so make
405 * an "add 0" request really be "set to 0".
408 tn->limit = tn->count = 0;
415 tm = &this_vlib_main->trace_main;
416 tm->trace_enable = 1;
421 static clib_error_t *
422 cli_add_trace_buffer (vlib_main_t * vm,
423 unformat_input_t * input, vlib_cli_command_t * cmd)
425 unformat_input_t _line_input, *line_input = &_line_input;
430 clib_error_t *error = 0;
432 if (!unformat_user (input, unformat_line_input, line_input))
435 if (vnet_trace_placeholder == 0)
436 vec_validate_aligned (vnet_trace_placeholder, 2048,
437 CLIB_CACHE_LINE_BYTES);
439 while (unformat_check_input (line_input) != (uword) UNFORMAT_END_OF_INPUT)
441 if (unformat (line_input, "%U %d",
442 unformat_vlib_node, vm, &node_index, &add))
444 else if (unformat (line_input, "verbose"))
446 else if (unformat (line_input, "filter"))
450 error = clib_error_create ("expected NODE COUNT, got `%U'",
451 format_unformat_error, line_input);
456 node = vlib_get_node (vm, node_index);
458 if ((node->flags & VLIB_NODE_FLAG_TRACE_SUPPORTED) == 0)
460 error = clib_error_create ("node '%U' doesn't support per-node "
461 "tracing. There may be another way to "
462 "initiate trace on this node.",
463 format_vlib_node_name, vm, node_index);
469 if (vlib_enable_disable_pkt_trace_filter (1 /* enable */ ))
471 error = clib_error_create ("No packet trace filter configured...");
476 trace_update_capture_options (add, node_index, filter, verbose);
479 unformat_free (line_input);
485 VLIB_CLI_COMMAND (add_trace_cli,static) = {
487 .short_help = "trace add <input-graph-node> <add'l-pkts-for-node-> [filter] [verbose]",
488 .function = cli_add_trace_buffer,
493 * Configure a filter for packet traces.
495 * This supplements the packet trace feature so that only packets matching
496 * the filter are included in the trace. Currently the only filter is to
497 * keep packets that include a certain node in the trace or exclude a certain
500 * The count of traced packets in the "trace add" command is still used to
501 * create a certain number of traces. The "trace filter" command specifies
502 * how many of those packets should be retained in the trace.
504 * For example, 1Mpps of traffic is arriving and one of those packets is being
505 * dropped. To capture the trace for only that dropped packet, you can do:
506 * trace filter include error-drop 1
507 * trace add dpdk-input 1000000
511 * Note that the filter could be implemented by capturing all traces and just
512 * reducing traces displayed by the "show trace" function. But that would
513 * require a lot of memory for storing the traces, making that infeasible.
515 * To remove traces from the trace pool that do not include a certain node
516 * requires that the trace be "complete" before applying the filter. To
517 * accomplish this, the trace pool is filtered upon each iteraction of the
518 * main vlib loop. Doing so keeps the number of allocated traces down to a
519 * reasonably low number. This requires that tracing for a buffer is not
520 * performed after the vlib main loop interation completes. i.e. you can't
521 * save away a buffer temporarily then inject it back into the graph and
522 * expect that the trace_index is still valid (such as a traffic manager might
523 * do). A new trace buffer should be allocated for those types of packets.
525 * The filter can be extended to support multiple nodes and other match
526 * criteria (e.g. input sw_if_index, mac address) but for now just checks if
527 * a specified node is in the trace or not in the trace.
531 trace_filter_set (u32 node_index, u32 flag, u32 count)
536 vlib_trace_main_t *tm;
538 tm = &this_vlib_main->trace_main;
539 tm->filter_node_index = node_index;
540 tm->filter_flag = flag;
541 tm->filter_count = count;
544 * Clear the trace limits to stop any in-progress tracing
545 * Prevents runaway trace allocations when the filter changes
548 vec_free (tm->nodes);
554 static clib_error_t *
555 cli_filter_trace (vlib_main_t * vm,
556 unformat_input_t * input, vlib_cli_command_t * cmd)
558 u32 filter_node_index;
562 if (unformat (input, "include %U %d",
563 unformat_vlib_node, vm, &filter_node_index, &filter_count))
565 filter_flag = FILTER_FLAG_INCLUDE;
567 else if (unformat (input, "exclude %U %d",
568 unformat_vlib_node, vm, &filter_node_index,
571 filter_flag = FILTER_FLAG_EXCLUDE;
573 else if (unformat (input, "none"))
575 filter_flag = FILTER_FLAG_NONE;
576 filter_node_index = 0;
582 ("expected 'include NODE COUNT' or 'exclude NODE COUNT' or 'none', got `%U'",
583 format_unformat_error, input);
585 trace_filter_set (filter_node_index, filter_flag, filter_count);
591 VLIB_CLI_COMMAND (filter_trace_cli,static) = {
592 .path = "trace filter",
593 .short_help = "trace filter none | [include|exclude] NODE COUNT",
594 .function = cli_filter_trace,
598 static clib_error_t *
599 cli_clear_trace_buffer (vlib_main_t * vm,
600 unformat_input_t * input, vlib_cli_command_t * cmd)
602 vlib_trace_stop_and_clear ();
607 VLIB_CLI_COMMAND (clear_trace_cli,static) = {
608 .path = "clear trace",
609 .short_help = "Clear trace buffer and free memory",
610 .function = cli_clear_trace_buffer,
614 /* Placeholder function to get us linked in. */
616 vlib_trace_cli_reference (void)
621 vnet_is_packet_traced (vlib_buffer_t * b,
622 u32 classify_table_index, int func)
623 __attribute__ ((weak));
626 vnet_is_packet_traced (vlib_buffer_t * b, u32 classify_table_index, int func)
628 clib_warning ("BUG: STUB called");
633 vlib_add_trace (vlib_main_t * vm,
634 vlib_node_runtime_t * r, vlib_buffer_t * b, u32 n_data_bytes)
636 return vlib_add_trace_inline (vm, r, b, n_data_bytes);
642 * fd.io coding-style-patch-verification: ON
645 * eval: (c-set-style "gnu")