Fix: test: proper redirection of stderr to stdout
[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 #include "lttng-sessiond.h"
36
37 /*
38 * Return allocated full pathname of the session using the consumer trace path
39 * and subdir if available. On a successful allocation, the directory of the
40 * trace is created with the session credentials.
41 *
42 * The caller can safely free(3) the returned value. On error, NULL is
43 * returned.
44 */
45 static char *setup_trace_path(struct consumer_output *consumer,
46 struct ust_app_session *ua_sess)
47 {
48 int ret;
49 char *pathname;
50
51 assert(consumer);
52 assert(ua_sess);
53
54 health_code_update();
55
56 /* Allocate our self the string to make sure we never exceed PATH_MAX. */
57 pathname = zmalloc(PATH_MAX);
58 if (!pathname) {
59 goto error;
60 }
61
62 /* Get correct path name destination */
63 if (consumer->type == CONSUMER_DST_LOCAL) {
64 /* Set application path to the destination path */
65 ret = snprintf(pathname, PATH_MAX, "%s%s%s",
66 consumer->dst.trace_path, consumer->subdir, ua_sess->path);
67 if (ret < 0) {
68 PERROR("snprintf channel path");
69 goto error;
70 }
71
72 /* Create directory. Ignore if exist. */
73 ret = run_as_mkdir_recursive(pathname, S_IRWXU | S_IRWXG,
74 ua_sess->euid, ua_sess->egid);
75 if (ret < 0) {
76 if (errno != EEXIST) {
77 ERR("Trace directory creation error");
78 goto error;
79 }
80 }
81 } else {
82 ret = snprintf(pathname, PATH_MAX, "%s%s", consumer->subdir,
83 ua_sess->path);
84 if (ret < 0) {
85 PERROR("snprintf channel path");
86 goto error;
87 }
88 }
89
90 return pathname;
91
92 error:
93 free(pathname);
94 return NULL;
95 }
96
97 /*
98 * Send a single channel to the consumer using command ASK_CHANNEL_CREATION.
99 *
100 * Consumer socket lock MUST be acquired before calling this.
101 */
102 static int ask_channel_creation(struct ust_app_session *ua_sess,
103 struct ust_app_channel *ua_chan, struct consumer_output *consumer,
104 struct consumer_socket *socket, struct ust_registry_session *registry)
105 {
106 int ret, output;
107 uint32_t chan_id;
108 uint64_t key, chan_reg_key;
109 char *pathname = NULL;
110 struct lttcomm_consumer_msg msg;
111 struct ust_registry_channel *chan_reg;
112 char shm_path[PATH_MAX] = "";
113 char root_shm_path[PATH_MAX] = "";
114
115 assert(ua_sess);
116 assert(ua_chan);
117 assert(socket);
118 assert(consumer);
119 assert(registry);
120
121 DBG2("Asking UST consumer for channel");
122
123 /* Get and create full trace path of session. */
124 if (ua_sess->output_traces) {
125 pathname = setup_trace_path(consumer, ua_sess);
126 if (!pathname) {
127 ret = -1;
128 goto error;
129 }
130 }
131
132 /* Depending on the buffer type, a different channel key is used. */
133 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
134 chan_reg_key = ua_chan->tracing_channel_id;
135 } else {
136 chan_reg_key = ua_chan->key;
137 }
138
139 if (ua_chan->attr.type == LTTNG_UST_CHAN_METADATA) {
140 chan_id = -1U;
141 /*
142 * Metadata channels shm_path (buffers) are handled within
143 * session daemon. Consumer daemon should not try to create
144 * those buffer files.
145 */
146 } else {
147 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
148 assert(chan_reg);
149 chan_id = chan_reg->chan_id;
150 if (ua_sess->shm_path[0]) {
151 strncpy(shm_path, ua_sess->shm_path, sizeof(shm_path));
152 shm_path[sizeof(shm_path) - 1] = '\0';
153 strncat(shm_path, "/",
154 sizeof(shm_path) - strlen(shm_path) - 1);
155 strncat(shm_path, ua_chan->name,
156 sizeof(shm_path) - strlen(shm_path) - 1);
157 strncat(shm_path, "_",
158 sizeof(shm_path) - strlen(shm_path) - 1);
159 }
160 strncpy(root_shm_path, ua_sess->root_shm_path, sizeof(root_shm_path));
161 root_shm_path[sizeof(root_shm_path) - 1] = '\0';
162 }
163
164 switch (ua_chan->attr.output) {
165 case LTTNG_UST_MMAP:
166 default:
167 output = LTTNG_EVENT_MMAP;
168 break;
169 }
170
171 consumer_init_ask_channel_comm_msg(&msg,
172 ua_chan->attr.subbuf_size,
173 ua_chan->attr.num_subbuf,
174 ua_chan->attr.overwrite,
175 ua_chan->attr.switch_timer_interval,
176 ua_chan->attr.read_timer_interval,
177 ua_sess->live_timer_interval,
178 ua_chan->monitor_timer_interval,
179 output,
180 (int) ua_chan->attr.type,
181 ua_sess->tracing_id,
182 pathname,
183 ua_chan->name,
184 ua_sess->euid,
185 ua_sess->egid,
186 consumer->net_seq_index,
187 ua_chan->key,
188 registry->uuid,
189 chan_id,
190 ua_chan->tracefile_size,
191 ua_chan->tracefile_count,
192 ua_sess->id,
193 ua_sess->output_traces,
194 ua_sess->uid,
195 root_shm_path, shm_path);
196
197 health_code_update();
198
199 ret = consumer_socket_send(socket, &msg, sizeof(msg));
200 if (ret < 0) {
201 goto error;
202 }
203
204 ret = consumer_recv_status_channel(socket, &key,
205 &ua_chan->expected_stream_count);
206 if (ret < 0) {
207 goto error;
208 }
209 /* Communication protocol error. */
210 assert(key == ua_chan->key);
211 /* We need at least one where 1 stream for 1 cpu. */
212 if (ua_sess->output_traces) {
213 assert(ua_chan->expected_stream_count > 0);
214 }
215
216 DBG2("UST ask channel %" PRIu64 " successfully done with %u stream(s)", key,
217 ua_chan->expected_stream_count);
218
219 error:
220 free(pathname);
221 health_code_update();
222 return ret;
223 }
224
225 /*
226 * Ask consumer to create a channel for a given session.
227 *
228 * Session list and rcu read side locks must be held by the caller.
229 *
230 * Returns 0 on success else a negative value.
231 */
232 int ust_consumer_ask_channel(struct ust_app_session *ua_sess,
233 struct ust_app_channel *ua_chan, struct consumer_output *consumer,
234 struct consumer_socket *socket, struct ust_registry_session *registry)
235 {
236 int ret;
237 struct ltt_session *session;
238
239 assert(ua_sess);
240 assert(ua_chan);
241 assert(consumer);
242 assert(socket);
243 assert(registry);
244
245 if (!consumer->enabled) {
246 ret = -LTTNG_ERR_NO_CONSUMER;
247 DBG3("Consumer is disabled");
248 goto error;
249 }
250
251 session = session_find_by_id(ua_sess->tracing_id);
252 assert(session);
253
254 pthread_mutex_lock(socket->lock);
255 ret = ask_channel_creation(ua_sess, ua_chan, consumer, socket, registry);
256 pthread_mutex_unlock(socket->lock);
257 if (ret < 0) {
258 ERR("ask_channel_creation consumer command failed");
259 goto error;
260 }
261
262 error:
263 return ret;
264 }
265
266 /*
267 * Send a get channel command to consumer using the given channel key. The
268 * channel object is populated and the stream list.
269 *
270 * Return 0 on success else a negative value.
271 */
272 int ust_consumer_get_channel(struct consumer_socket *socket,
273 struct ust_app_channel *ua_chan)
274 {
275 int ret;
276 struct lttcomm_consumer_msg msg;
277
278 assert(ua_chan);
279 assert(socket);
280
281 memset(&msg, 0, sizeof(msg));
282 msg.cmd_type = LTTNG_CONSUMER_GET_CHANNEL;
283 msg.u.get_channel.key = ua_chan->key;
284
285 pthread_mutex_lock(socket->lock);
286 health_code_update();
287
288 /* Send command and wait for OK reply. */
289 ret = consumer_send_msg(socket, &msg);
290 if (ret < 0) {
291 goto error;
292 }
293
294 /* First, get the channel from consumer. */
295 ret = ustctl_recv_channel_from_consumer(*socket->fd_ptr, &ua_chan->obj);
296 if (ret < 0) {
297 if (ret != -EPIPE) {
298 ERR("Error recv channel from consumer %d with ret %d",
299 *socket->fd_ptr, ret);
300 } else {
301 DBG3("UST app recv channel from consumer. Consumer is dead.");
302 }
303 goto error;
304 }
305
306 /* Next, get all streams. */
307 while (1) {
308 struct ust_app_stream *stream;
309
310 /* Create UST stream */
311 stream = ust_app_alloc_stream();
312 if (stream == NULL) {
313 ret = -ENOMEM;
314 goto error;
315 }
316
317 /* Stream object is populated by this call if successful. */
318 ret = ustctl_recv_stream_from_consumer(*socket->fd_ptr, &stream->obj);
319 if (ret < 0) {
320 free(stream);
321 if (ret == -LTTNG_UST_ERR_NOENT) {
322 DBG3("UST app consumer has no more stream available");
323 ret = 0;
324 break;
325 }
326 if (ret != -EPIPE) {
327 ERR("Recv stream from consumer %d with ret %d",
328 *socket->fd_ptr, ret);
329 } else {
330 DBG3("UST app recv stream from consumer. Consumer is dead.");
331 }
332 goto error;
333 }
334
335 /* Order is important this is why a list is used. */
336 cds_list_add_tail(&stream->list, &ua_chan->streams.head);
337 ua_chan->streams.count++;
338
339 DBG2("UST app stream %d received successfully", ua_chan->streams.count);
340 }
341
342 /* This MUST match or else we have a synchronization problem. */
343 assert(ua_chan->expected_stream_count == ua_chan->streams.count);
344
345 /* Wait for confirmation that we can proceed with the streams. */
346 ret = consumer_recv_status_reply(socket);
347 if (ret < 0) {
348 goto error;
349 }
350
351 error:
352 health_code_update();
353 pthread_mutex_unlock(socket->lock);
354 return ret;
355 }
356
357 /*
358 * Send a destroy channel command to consumer using the given channel key.
359 *
360 * Note that this command MUST be used prior to a successful
361 * LTTNG_CONSUMER_GET_CHANNEL because once this command is done successfully,
362 * the streams are dispatched to the consumer threads and MUST be teardown
363 * through the hang up process.
364 *
365 * Return 0 on success else a negative value.
366 */
367 int ust_consumer_destroy_channel(struct consumer_socket *socket,
368 struct ust_app_channel *ua_chan)
369 {
370 int ret;
371 struct lttcomm_consumer_msg msg;
372
373 assert(ua_chan);
374 assert(socket);
375
376 memset(&msg, 0, sizeof(msg));
377 msg.cmd_type = LTTNG_CONSUMER_DESTROY_CHANNEL;
378 msg.u.destroy_channel.key = ua_chan->key;
379
380 pthread_mutex_lock(socket->lock);
381 health_code_update();
382
383 ret = consumer_send_msg(socket, &msg);
384 if (ret < 0) {
385 goto error;
386 }
387
388 error:
389 health_code_update();
390 pthread_mutex_unlock(socket->lock);
391 return ret;
392 }
393
394 /*
395 * Send a given stream to UST tracer.
396 *
397 * On success return 0 else a negative value.
398 */
399 int ust_consumer_send_stream_to_ust(struct ust_app *app,
400 struct ust_app_channel *channel, struct ust_app_stream *stream)
401 {
402 int ret;
403
404 assert(app);
405 assert(stream);
406 assert(channel);
407
408 DBG2("UST consumer send stream to app %d", app->sock);
409
410 /* Relay stream to application. */
411 pthread_mutex_lock(&app->sock_lock);
412 ret = ustctl_send_stream_to_ust(app->sock, channel->obj, stream->obj);
413 pthread_mutex_unlock(&app->sock_lock);
414 if (ret < 0) {
415 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
416 ERR("ustctl send stream handle %d to app pid: %d with ret %d",
417 stream->obj->handle, app->pid, ret);
418 } else {
419 DBG3("UST app send stream to ust failed. Application is dead.");
420 }
421 goto error;
422 }
423 channel->handle = channel->obj->handle;
424
425 error:
426 return ret;
427 }
428
429 /*
430 * Send channel previously received from the consumer to the UST tracer.
431 *
432 * On success return 0 else a negative value.
433 */
434 int ust_consumer_send_channel_to_ust(struct ust_app *app,
435 struct ust_app_session *ua_sess, struct ust_app_channel *channel)
436 {
437 int ret;
438
439 assert(app);
440 assert(ua_sess);
441 assert(channel);
442 assert(channel->obj);
443
444 DBG2("UST app send channel to sock %d pid %d (name: %s, key: %" PRIu64 ")",
445 app->sock, app->pid, channel->name, channel->tracing_channel_id);
446
447 /* Send stream to application. */
448 pthread_mutex_lock(&app->sock_lock);
449 ret = ustctl_send_channel_to_ust(app->sock, ua_sess->handle, channel->obj);
450 pthread_mutex_unlock(&app->sock_lock);
451 if (ret < 0) {
452 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
453 ERR("Error ustctl send channel %s to app pid: %d with ret %d",
454 channel->name, app->pid, ret);
455 } else {
456 DBG3("UST app send channel to ust failed. Application is dead.");
457 }
458 goto error;
459 }
460
461 error:
462 return ret;
463 }
464
465 /*
466 * Handle the metadata requests from the UST consumer
467 *
468 * Return 0 on success else a negative value.
469 */
470 int ust_consumer_metadata_request(struct consumer_socket *socket)
471 {
472 int ret;
473 ssize_t ret_push;
474 struct lttcomm_metadata_request_msg request;
475 struct buffer_reg_uid *reg_uid;
476 struct ust_registry_session *ust_reg;
477 struct lttcomm_consumer_msg msg;
478
479 assert(socket);
480
481 rcu_read_lock();
482 health_code_update();
483
484 /* Wait for a metadata request */
485 pthread_mutex_lock(socket->lock);
486 ret = consumer_socket_recv(socket, &request, sizeof(request));
487 pthread_mutex_unlock(socket->lock);
488 if (ret < 0) {
489 goto end;
490 }
491
492 DBG("Metadata request received for session %" PRIu64 ", key %" PRIu64,
493 request.session_id, request.key);
494
495 reg_uid = buffer_reg_uid_find(request.session_id,
496 request.bits_per_long, request.uid);
497 if (reg_uid) {
498 ust_reg = reg_uid->registry->reg.ust;
499 } else {
500 struct buffer_reg_pid *reg_pid =
501 buffer_reg_pid_find(request.session_id_per_pid);
502 if (!reg_pid) {
503 DBG("PID registry not found for session id %" PRIu64,
504 request.session_id_per_pid);
505
506 memset(&msg, 0, sizeof(msg));
507 msg.cmd_type = LTTNG_ERR_UND;
508 (void) consumer_send_msg(socket, &msg);
509 /*
510 * This is possible since the session might have been destroyed
511 * during a consumer metadata request. So here, return gracefully
512 * because the destroy session will push the remaining metadata to
513 * the consumer.
514 */
515 ret = 0;
516 goto end;
517 }
518 ust_reg = reg_pid->registry->reg.ust;
519 }
520 assert(ust_reg);
521
522 pthread_mutex_lock(&ust_reg->lock);
523 ret_push = ust_app_push_metadata(ust_reg, socket, 1);
524 pthread_mutex_unlock(&ust_reg->lock);
525 if (ret_push == -EPIPE) {
526 DBG("Application or relay closed while pushing metadata");
527 } else if (ret_push < 0) {
528 ERR("Pushing metadata");
529 ret = -1;
530 goto end;
531 } else {
532 DBG("UST Consumer metadata pushed successfully");
533 }
534 ret = 0;
535
536 end:
537 rcu_read_unlock();
538 return ret;
539 }
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