Tests: remove flaky '*' kernel wildcard test
[lttng-tools.git] / src / bin / lttng-sessiond / ust-consumer.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 #define _LGPL_SOURCE
19 #include <errno.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <unistd.h>
24 #include <inttypes.h>
25
26 #include <common/common.h>
27 #include <common/consumer/consumer.h>
28 #include <common/defaults.h>
29
30 #include "consumer.h"
31 #include "health-sessiond.h"
32 #include "ust-consumer.h"
33 #include "buffer-registry.h"
34 #include "session.h"
35
36 /*
37 * Return allocated full pathname of the session using the consumer trace path
38 * and subdir if available. On a successful allocation, the directory of the
39 * trace is created with the session credentials.
40 *
41 * The caller can safely free(3) the returned value. On error, NULL is
42 * returned.
43 */
44 static char *setup_trace_path(struct consumer_output *consumer,
45 struct ust_app_session *ua_sess)
46 {
47 int ret;
48 char *pathname;
49
50 assert(consumer);
51 assert(ua_sess);
52
53 health_code_update();
54
55 /* Allocate our self the string to make sure we never exceed PATH_MAX. */
56 pathname = zmalloc(PATH_MAX);
57 if (!pathname) {
58 goto error;
59 }
60
61 /* Get correct path name destination */
62 if (consumer->type == CONSUMER_DST_LOCAL) {
63 /* Set application path to the destination path */
64 ret = snprintf(pathname, PATH_MAX, "%s%s%s",
65 consumer->dst.trace_path, consumer->subdir, ua_sess->path);
66 if (ret < 0) {
67 PERROR("snprintf channel path");
68 goto error;
69 }
70
71 /* Create directory. Ignore if exist. */
72 ret = run_as_mkdir_recursive(pathname, S_IRWXU | S_IRWXG,
73 ua_sess->euid, ua_sess->egid);
74 if (ret < 0) {
75 if (errno != EEXIST) {
76 ERR("Trace directory creation error");
77 goto error;
78 }
79 }
80 } else {
81 ret = snprintf(pathname, PATH_MAX, "%s%s", consumer->subdir,
82 ua_sess->path);
83 if (ret < 0) {
84 PERROR("snprintf channel path");
85 goto error;
86 }
87 }
88
89 return pathname;
90
91 error:
92 free(pathname);
93 return NULL;
94 }
95
96 /*
97 * Send a single channel to the consumer using command ADD_CHANNEL.
98 *
99 * Consumer socket lock MUST be acquired before calling this.
100 */
101 static int ask_channel_creation(struct ust_app_session *ua_sess,
102 struct ust_app_channel *ua_chan, struct consumer_output *consumer,
103 struct consumer_socket *socket, struct ust_registry_session *registry)
104 {
105 int ret, output;
106 uint32_t chan_id;
107 uint64_t key, chan_reg_key;
108 char *pathname = NULL;
109 struct lttcomm_consumer_msg msg;
110 struct ust_registry_channel *chan_reg;
111 char shm_path[PATH_MAX] = "";
112 char root_shm_path[PATH_MAX] = "";
113
114 assert(ua_sess);
115 assert(ua_chan);
116 assert(socket);
117 assert(consumer);
118 assert(registry);
119
120 DBG2("Asking UST consumer for channel");
121
122 /* Get and create full trace path of session. */
123 if (ua_sess->output_traces) {
124 pathname = setup_trace_path(consumer, ua_sess);
125 if (!pathname) {
126 ret = -1;
127 goto error;
128 }
129 }
130
131 /* Depending on the buffer type, a different channel key is used. */
132 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
133 chan_reg_key = ua_chan->tracing_channel_id;
134 } else {
135 chan_reg_key = ua_chan->key;
136 }
137
138 if (ua_chan->attr.type == LTTNG_UST_CHAN_METADATA) {
139 chan_id = -1U;
140 /*
141 * Metadata channels shm_path (buffers) are handled within
142 * session daemon. Consumer daemon should not try to create
143 * those buffer files.
144 */
145 } else {
146 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
147 assert(chan_reg);
148 chan_id = chan_reg->chan_id;
149 if (ua_sess->shm_path[0]) {
150 strncpy(shm_path, ua_sess->shm_path, sizeof(shm_path));
151 shm_path[sizeof(shm_path) - 1] = '\0';
152 strncat(shm_path, "/",
153 sizeof(shm_path) - strlen(shm_path) - 1);
154 strncat(shm_path, ua_chan->name,
155 sizeof(shm_path) - strlen(shm_path) - 1);
156 strncat(shm_path, "_",
157 sizeof(shm_path) - strlen(shm_path) - 1);
158 }
159 strncpy(root_shm_path, ua_sess->root_shm_path, sizeof(root_shm_path));
160 root_shm_path[sizeof(root_shm_path) - 1] = '\0';
161 }
162
163 switch (ua_chan->attr.output) {
164 case LTTNG_UST_MMAP:
165 default:
166 output = LTTNG_EVENT_MMAP;
167 break;
168 }
169
170 consumer_init_ask_channel_comm_msg(&msg,
171 ua_chan->attr.subbuf_size,
172 ua_chan->attr.num_subbuf,
173 ua_chan->attr.overwrite,
174 ua_chan->attr.switch_timer_interval,
175 ua_chan->attr.read_timer_interval,
176 ua_sess->live_timer_interval,
177 output,
178 (int) ua_chan->attr.type,
179 ua_sess->tracing_id,
180 pathname,
181 ua_chan->name,
182 ua_sess->euid,
183 ua_sess->egid,
184 consumer->net_seq_index,
185 ua_chan->key,
186 registry->uuid,
187 chan_id,
188 ua_chan->tracefile_size,
189 ua_chan->tracefile_count,
190 ua_sess->id,
191 ua_sess->output_traces,
192 ua_sess->uid,
193 root_shm_path, shm_path);
194
195 health_code_update();
196
197 ret = consumer_socket_send(socket, &msg, sizeof(msg));
198 if (ret < 0) {
199 goto error;
200 }
201
202 ret = consumer_recv_status_channel(socket, &key,
203 &ua_chan->expected_stream_count);
204 if (ret < 0) {
205 goto error;
206 }
207 /* Communication protocol error. */
208 assert(key == ua_chan->key);
209 /* We need at least one where 1 stream for 1 cpu. */
210 if (ua_sess->output_traces) {
211 assert(ua_chan->expected_stream_count > 0);
212 }
213
214 DBG2("UST ask channel %" PRIu64 " successfully done with %u stream(s)", key,
215 ua_chan->expected_stream_count);
216
217 error:
218 free(pathname);
219 health_code_update();
220 return ret;
221 }
222
223 /*
224 * Ask consumer to create a channel for a given session.
225 *
226 * Returns 0 on success else a negative value.
227 */
228 int ust_consumer_ask_channel(struct ust_app_session *ua_sess,
229 struct ust_app_channel *ua_chan, struct consumer_output *consumer,
230 struct consumer_socket *socket, struct ust_registry_session *registry)
231 {
232 int ret;
233
234 assert(ua_sess);
235 assert(ua_chan);
236 assert(consumer);
237 assert(socket);
238 assert(registry);
239
240 if (!consumer->enabled) {
241 ret = -LTTNG_ERR_NO_CONSUMER;
242 DBG3("Consumer is disabled");
243 goto error;
244 }
245
246 pthread_mutex_lock(socket->lock);
247 ret = ask_channel_creation(ua_sess, ua_chan, consumer, socket, registry);
248 pthread_mutex_unlock(socket->lock);
249 if (ret < 0) {
250 goto error;
251 }
252
253 error:
254 return ret;
255 }
256
257 /*
258 * Send a get channel command to consumer using the given channel key. The
259 * channel object is populated and the stream list.
260 *
261 * Return 0 on success else a negative value.
262 */
263 int ust_consumer_get_channel(struct consumer_socket *socket,
264 struct ust_app_channel *ua_chan)
265 {
266 int ret;
267 struct lttcomm_consumer_msg msg;
268
269 assert(ua_chan);
270 assert(socket);
271
272 memset(&msg, 0, sizeof(msg));
273 msg.cmd_type = LTTNG_CONSUMER_GET_CHANNEL;
274 msg.u.get_channel.key = ua_chan->key;
275
276 pthread_mutex_lock(socket->lock);
277 health_code_update();
278
279 /* Send command and wait for OK reply. */
280 ret = consumer_send_msg(socket, &msg);
281 if (ret < 0) {
282 goto error;
283 }
284
285 /* First, get the channel from consumer. */
286 ret = ustctl_recv_channel_from_consumer(*socket->fd_ptr, &ua_chan->obj);
287 if (ret < 0) {
288 if (ret != -EPIPE) {
289 ERR("Error recv channel from consumer %d with ret %d",
290 *socket->fd_ptr, ret);
291 } else {
292 DBG3("UST app recv channel from consumer. Consumer is dead.");
293 }
294 goto error;
295 }
296
297 /* Next, get all streams. */
298 while (1) {
299 struct ust_app_stream *stream;
300
301 /* Create UST stream */
302 stream = ust_app_alloc_stream();
303 if (stream == NULL) {
304 ret = -ENOMEM;
305 goto error;
306 }
307
308 /* Stream object is populated by this call if successful. */
309 ret = ustctl_recv_stream_from_consumer(*socket->fd_ptr, &stream->obj);
310 if (ret < 0) {
311 free(stream);
312 if (ret == -LTTNG_UST_ERR_NOENT) {
313 DBG3("UST app consumer has no more stream available");
314 ret = 0;
315 break;
316 }
317 if (ret != -EPIPE) {
318 ERR("Recv stream from consumer %d with ret %d",
319 *socket->fd_ptr, ret);
320 } else {
321 DBG3("UST app recv stream from consumer. Consumer is dead.");
322 }
323 goto error;
324 }
325
326 /* Order is important this is why a list is used. */
327 cds_list_add_tail(&stream->list, &ua_chan->streams.head);
328 ua_chan->streams.count++;
329
330 DBG2("UST app stream %d received successfully", ua_chan->streams.count);
331 }
332
333 /* This MUST match or else we have a synchronization problem. */
334 assert(ua_chan->expected_stream_count == ua_chan->streams.count);
335
336 /* Wait for confirmation that we can proceed with the streams. */
337 ret = consumer_recv_status_reply(socket);
338 if (ret < 0) {
339 goto error;
340 }
341
342 error:
343 health_code_update();
344 pthread_mutex_unlock(socket->lock);
345 return ret;
346 }
347
348 /*
349 * Send a destroy channel command to consumer using the given channel key.
350 *
351 * Note that this command MUST be used prior to a successful
352 * LTTNG_CONSUMER_GET_CHANNEL because once this command is done successfully,
353 * the streams are dispatched to the consumer threads and MUST be teardown
354 * through the hang up process.
355 *
356 * Return 0 on success else a negative value.
357 */
358 int ust_consumer_destroy_channel(struct consumer_socket *socket,
359 struct ust_app_channel *ua_chan)
360 {
361 int ret;
362 struct lttcomm_consumer_msg msg;
363
364 assert(ua_chan);
365 assert(socket);
366
367 memset(&msg, 0, sizeof(msg));
368 msg.cmd_type = LTTNG_CONSUMER_DESTROY_CHANNEL;
369 msg.u.destroy_channel.key = ua_chan->key;
370
371 pthread_mutex_lock(socket->lock);
372 health_code_update();
373
374 ret = consumer_send_msg(socket, &msg);
375 if (ret < 0) {
376 goto error;
377 }
378
379 error:
380 health_code_update();
381 pthread_mutex_unlock(socket->lock);
382 return ret;
383 }
384
385 /*
386 * Send a given stream to UST tracer.
387 *
388 * On success return 0 else a negative value.
389 */
390 int ust_consumer_send_stream_to_ust(struct ust_app *app,
391 struct ust_app_channel *channel, struct ust_app_stream *stream)
392 {
393 int ret;
394
395 assert(app);
396 assert(stream);
397 assert(channel);
398
399 DBG2("UST consumer send stream to app %d", app->sock);
400
401 /* Relay stream to application. */
402 pthread_mutex_lock(&app->sock_lock);
403 ret = ustctl_send_stream_to_ust(app->sock, channel->obj, stream->obj);
404 pthread_mutex_unlock(&app->sock_lock);
405 if (ret < 0) {
406 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
407 ERR("ustctl send stream handle %d to app pid: %d with ret %d",
408 stream->obj->handle, app->pid, ret);
409 } else {
410 DBG3("UST app send stream to ust failed. Application is dead.");
411 }
412 goto error;
413 }
414 channel->handle = channel->obj->handle;
415
416 error:
417 return ret;
418 }
419
420 /*
421 * Send channel previously received from the consumer to the UST tracer.
422 *
423 * On success return 0 else a negative value.
424 */
425 int ust_consumer_send_channel_to_ust(struct ust_app *app,
426 struct ust_app_session *ua_sess, struct ust_app_channel *channel)
427 {
428 int ret;
429
430 assert(app);
431 assert(ua_sess);
432 assert(channel);
433 assert(channel->obj);
434
435 DBG2("UST app send channel to sock %d pid %d (name: %s, key: %" PRIu64 ")",
436 app->sock, app->pid, channel->name, channel->tracing_channel_id);
437
438 /* Send stream to application. */
439 pthread_mutex_lock(&app->sock_lock);
440 ret = ustctl_send_channel_to_ust(app->sock, ua_sess->handle, channel->obj);
441 pthread_mutex_unlock(&app->sock_lock);
442 if (ret < 0) {
443 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
444 ERR("Error ustctl send channel %s to app pid: %d with ret %d",
445 channel->name, app->pid, ret);
446 } else {
447 DBG3("UST app send channel to ust failed. Application is dead.");
448 }
449 goto error;
450 }
451
452 error:
453 return ret;
454 }
455
456 /*
457 * Handle the metadata requests from the UST consumer
458 *
459 * Return 0 on success else a negative value.
460 */
461 int ust_consumer_metadata_request(struct consumer_socket *socket)
462 {
463 int ret;
464 ssize_t ret_push;
465 struct lttcomm_metadata_request_msg request;
466 struct buffer_reg_uid *reg_uid;
467 struct ust_registry_session *ust_reg;
468 struct lttcomm_consumer_msg msg;
469
470 assert(socket);
471
472 rcu_read_lock();
473 health_code_update();
474
475 /* Wait for a metadata request */
476 pthread_mutex_lock(socket->lock);
477 ret = consumer_socket_recv(socket, &request, sizeof(request));
478 pthread_mutex_unlock(socket->lock);
479 if (ret < 0) {
480 goto end;
481 }
482
483 DBG("Metadata request received for session %" PRIu64 ", key %" PRIu64,
484 request.session_id, request.key);
485
486 reg_uid = buffer_reg_uid_find(request.session_id,
487 request.bits_per_long, request.uid);
488 if (reg_uid) {
489 ust_reg = reg_uid->registry->reg.ust;
490 } else {
491 struct buffer_reg_pid *reg_pid =
492 buffer_reg_pid_find(request.session_id_per_pid);
493 if (!reg_pid) {
494 DBG("PID registry not found for session id %" PRIu64,
495 request.session_id_per_pid);
496
497 memset(&msg, 0, sizeof(msg));
498 msg.cmd_type = LTTNG_ERR_UND;
499 (void) consumer_send_msg(socket, &msg);
500 /*
501 * This is possible since the session might have been destroyed
502 * during a consumer metadata request. So here, return gracefully
503 * because the destroy session will push the remaining metadata to
504 * the consumer.
505 */
506 ret = 0;
507 goto end;
508 }
509 ust_reg = reg_pid->registry->reg.ust;
510 }
511 assert(ust_reg);
512
513 pthread_mutex_lock(&ust_reg->lock);
514 ret_push = ust_app_push_metadata(ust_reg, socket, 1);
515 pthread_mutex_unlock(&ust_reg->lock);
516 if (ret_push == -EPIPE) {
517 DBG("Application or relay closed while pushing metadata");
518 } else if (ret_push < 0) {
519 ERR("Pushing metadata");
520 ret = -1;
521 goto end;
522 } else {
523 DBG("UST Consumer metadata pushed successfully");
524 }
525 ret = 0;
526
527 end:
528 rcu_read_unlock();
529 return ret;
530 }
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