Sessiond rotation thread
[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 /*
57 * Allocate the string ourself to make sure we never exceed
58 * LTTNG_PATH_MAX.
59 */
60 pathname = zmalloc(LTTNG_PATH_MAX);
61 if (!pathname) {
62 goto error;
63 }
64
65 /* Get correct path name destination */
66 if (consumer->type == CONSUMER_DST_LOCAL) {
67 /* Set application path to the destination path */
68 ret = snprintf(pathname, LTTNG_PATH_MAX, "%s%s%s%s",
69 consumer->dst.session_root_path,
70 consumer->chunk_path,
71 consumer->subdir, ua_sess->path);
72 if (ret < 0) {
73 PERROR("snprintf channel path");
74 goto error;
75 }
76
77 /* Create directory. Ignore if exist. */
78 ret = run_as_mkdir_recursive(pathname, S_IRWXU | S_IRWXG,
79 ua_sess->euid, ua_sess->egid);
80 if (ret < 0) {
81 if (errno != EEXIST) {
82 ERR("Trace directory creation error");
83 goto error;
84 }
85 }
86 } else {
87 ret = snprintf(pathname, LTTNG_PATH_MAX, "%s%s%s%s",
88 consumer->dst.net.base_dir,
89 consumer->chunk_path,
90 consumer->subdir,
91 ua_sess->path);
92 if (ret < 0) {
93 PERROR("snprintf channel path");
94 goto error;
95 }
96 }
97
98 return pathname;
99
100 error:
101 free(pathname);
102 return NULL;
103 }
104
105 /*
106 * Send a single channel to the consumer using command ASK_CHANNEL_CREATION.
107 *
108 * Consumer socket lock MUST be acquired before calling this.
109 */
110 static int ask_channel_creation(struct ust_app_session *ua_sess,
111 struct ust_app_channel *ua_chan, struct consumer_output *consumer,
112 struct consumer_socket *socket, struct ust_registry_session *registry)
113 {
114 int ret, output;
115 uint32_t chan_id;
116 uint64_t key, chan_reg_key;
117 char *pathname = NULL;
118 struct lttcomm_consumer_msg msg;
119 struct ust_registry_channel *chan_reg;
120 char shm_path[PATH_MAX] = "";
121 char root_shm_path[PATH_MAX] = "";
122
123 assert(ua_sess);
124 assert(ua_chan);
125 assert(socket);
126 assert(consumer);
127 assert(registry);
128
129 DBG2("Asking UST consumer for channel");
130
131 /* Get and create full trace path of session. */
132 if (ua_sess->output_traces) {
133 pathname = setup_trace_path(consumer, ua_sess);
134 if (!pathname) {
135 ret = -1;
136 goto error;
137 }
138 }
139
140 /* Depending on the buffer type, a different channel key is used. */
141 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
142 chan_reg_key = ua_chan->tracing_channel_id;
143 } else {
144 chan_reg_key = ua_chan->key;
145 }
146
147 if (ua_chan->attr.type == LTTNG_UST_CHAN_METADATA) {
148 chan_id = -1U;
149 /*
150 * Metadata channels shm_path (buffers) are handled within
151 * session daemon. Consumer daemon should not try to create
152 * those buffer files.
153 */
154 } else {
155 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
156 assert(chan_reg);
157 chan_id = chan_reg->chan_id;
158 if (ua_sess->shm_path[0]) {
159 strncpy(shm_path, ua_sess->shm_path, sizeof(shm_path));
160 shm_path[sizeof(shm_path) - 1] = '\0';
161 strncat(shm_path, "/",
162 sizeof(shm_path) - strlen(shm_path) - 1);
163 strncat(shm_path, ua_chan->name,
164 sizeof(shm_path) - strlen(shm_path) - 1);
165 strncat(shm_path, "_",
166 sizeof(shm_path) - strlen(shm_path) - 1);
167 }
168 strncpy(root_shm_path, ua_sess->root_shm_path, sizeof(root_shm_path));
169 root_shm_path[sizeof(root_shm_path) - 1] = '\0';
170 }
171
172 switch (ua_chan->attr.output) {
173 case LTTNG_UST_MMAP:
174 default:
175 output = LTTNG_EVENT_MMAP;
176 break;
177 }
178
179 consumer_init_ask_channel_comm_msg(&msg,
180 ua_chan->attr.subbuf_size,
181 ua_chan->attr.num_subbuf,
182 ua_chan->attr.overwrite,
183 ua_chan->attr.switch_timer_interval,
184 ua_chan->attr.read_timer_interval,
185 ua_sess->live_timer_interval,
186 ua_chan->monitor_timer_interval,
187 output,
188 (int) ua_chan->attr.type,
189 ua_sess->tracing_id,
190 pathname,
191 ua_chan->name,
192 ua_sess->euid,
193 ua_sess->egid,
194 consumer->net_seq_index,
195 ua_chan->key,
196 registry->uuid,
197 chan_id,
198 ua_chan->tracefile_size,
199 ua_chan->tracefile_count,
200 ua_sess->id,
201 ua_sess->output_traces,
202 ua_sess->uid,
203 ua_chan->attr.blocking_timeout,
204 root_shm_path, shm_path);
205
206 health_code_update();
207
208 ret = consumer_socket_send(socket, &msg, sizeof(msg));
209 if (ret < 0) {
210 goto error;
211 }
212
213 ret = consumer_recv_status_channel(socket, &key,
214 &ua_chan->expected_stream_count);
215 if (ret < 0) {
216 goto error;
217 }
218 /* Communication protocol error. */
219 assert(key == ua_chan->key);
220 /* We need at least one where 1 stream for 1 cpu. */
221 if (ua_sess->output_traces) {
222 assert(ua_chan->expected_stream_count > 0);
223 }
224
225 DBG2("UST ask channel %" PRIu64 " successfully done with %u stream(s)", key,
226 ua_chan->expected_stream_count);
227
228 error:
229 free(pathname);
230 health_code_update();
231 return ret;
232 }
233
234 /*
235 * Ask consumer to create a channel for a given session.
236 *
237 * Session list and rcu read side locks must be held by the caller.
238 *
239 * Returns 0 on success else a negative value.
240 */
241 int ust_consumer_ask_channel(struct ust_app_session *ua_sess,
242 struct ust_app_channel *ua_chan, struct consumer_output *consumer,
243 struct consumer_socket *socket, struct ust_registry_session *registry)
244 {
245 int ret;
246 struct ltt_session *session;
247
248 assert(ua_sess);
249 assert(ua_chan);
250 assert(consumer);
251 assert(socket);
252 assert(registry);
253
254 if (!consumer->enabled) {
255 ret = -LTTNG_ERR_NO_CONSUMER;
256 DBG3("Consumer is disabled");
257 goto error;
258 }
259
260 session = session_find_by_id(ua_sess->tracing_id);
261 assert(session);
262
263 pthread_mutex_lock(socket->lock);
264 ret = ask_channel_creation(ua_sess, ua_chan, consumer, socket, registry);
265 pthread_mutex_unlock(socket->lock);
266 if (ret < 0) {
267 ERR("ask_channel_creation consumer command failed");
268 goto error;
269 }
270
271 error:
272 return ret;
273 }
274
275 /*
276 * Send a get channel command to consumer using the given channel key. The
277 * channel object is populated and the stream list.
278 *
279 * Return 0 on success else a negative value.
280 */
281 int ust_consumer_get_channel(struct consumer_socket *socket,
282 struct ust_app_channel *ua_chan)
283 {
284 int ret;
285 struct lttcomm_consumer_msg msg;
286
287 assert(ua_chan);
288 assert(socket);
289
290 memset(&msg, 0, sizeof(msg));
291 msg.cmd_type = LTTNG_CONSUMER_GET_CHANNEL;
292 msg.u.get_channel.key = ua_chan->key;
293
294 pthread_mutex_lock(socket->lock);
295 health_code_update();
296
297 /* Send command and wait for OK reply. */
298 ret = consumer_send_msg(socket, &msg);
299 if (ret < 0) {
300 goto error;
301 }
302
303 /* First, get the channel from consumer. */
304 ret = ustctl_recv_channel_from_consumer(*socket->fd_ptr, &ua_chan->obj);
305 if (ret < 0) {
306 if (ret != -EPIPE) {
307 ERR("Error recv channel from consumer %d with ret %d",
308 *socket->fd_ptr, ret);
309 } else {
310 DBG3("UST app recv channel from consumer. Consumer is dead.");
311 }
312 goto error;
313 }
314
315 /* Next, get all streams. */
316 while (1) {
317 struct ust_app_stream *stream;
318
319 /* Create UST stream */
320 stream = ust_app_alloc_stream();
321 if (stream == NULL) {
322 ret = -ENOMEM;
323 goto error;
324 }
325
326 /* Stream object is populated by this call if successful. */
327 ret = ustctl_recv_stream_from_consumer(*socket->fd_ptr, &stream->obj);
328 if (ret < 0) {
329 free(stream);
330 if (ret == -LTTNG_UST_ERR_NOENT) {
331 DBG3("UST app consumer has no more stream available");
332 break;
333 }
334 if (ret != -EPIPE) {
335 ERR("Recv stream from consumer %d with ret %d",
336 *socket->fd_ptr, ret);
337 } else {
338 DBG3("UST app recv stream from consumer. Consumer is dead.");
339 }
340 goto error;
341 }
342
343 /* Order is important this is why a list is used. */
344 cds_list_add_tail(&stream->list, &ua_chan->streams.head);
345 ua_chan->streams.count++;
346
347 DBG2("UST app stream %d received successfully", ua_chan->streams.count);
348 }
349
350 /* This MUST match or else we have a synchronization problem. */
351 assert(ua_chan->expected_stream_count == ua_chan->streams.count);
352
353 /* Wait for confirmation that we can proceed with the streams. */
354 ret = consumer_recv_status_reply(socket);
355 if (ret < 0) {
356 goto error;
357 }
358
359 error:
360 health_code_update();
361 pthread_mutex_unlock(socket->lock);
362 return ret;
363 }
364
365 /*
366 * Send a destroy channel command to consumer using the given channel key.
367 *
368 * Note that this command MUST be used prior to a successful
369 * LTTNG_CONSUMER_GET_CHANNEL because once this command is done successfully,
370 * the streams are dispatched to the consumer threads and MUST be teardown
371 * through the hang up process.
372 *
373 * Return 0 on success else a negative value.
374 */
375 int ust_consumer_destroy_channel(struct consumer_socket *socket,
376 struct ust_app_channel *ua_chan)
377 {
378 int ret;
379 struct lttcomm_consumer_msg msg;
380
381 assert(ua_chan);
382 assert(socket);
383
384 memset(&msg, 0, sizeof(msg));
385 msg.cmd_type = LTTNG_CONSUMER_DESTROY_CHANNEL;
386 msg.u.destroy_channel.key = ua_chan->key;
387
388 pthread_mutex_lock(socket->lock);
389 health_code_update();
390
391 ret = consumer_send_msg(socket, &msg);
392 if (ret < 0) {
393 goto error;
394 }
395
396 error:
397 health_code_update();
398 pthread_mutex_unlock(socket->lock);
399 return ret;
400 }
401
402 /*
403 * Send a given stream to UST tracer.
404 *
405 * On success return 0 else a negative value.
406 */
407 int ust_consumer_send_stream_to_ust(struct ust_app *app,
408 struct ust_app_channel *channel, struct ust_app_stream *stream)
409 {
410 int ret;
411
412 assert(app);
413 assert(stream);
414 assert(channel);
415
416 DBG2("UST consumer send stream to app %d", app->sock);
417
418 /* Relay stream to application. */
419 pthread_mutex_lock(&app->sock_lock);
420 ret = ustctl_send_stream_to_ust(app->sock, channel->obj, stream->obj);
421 pthread_mutex_unlock(&app->sock_lock);
422 if (ret < 0) {
423 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
424 ERR("ustctl send stream handle %d to app pid: %d with ret %d",
425 stream->obj->handle, app->pid, ret);
426 } else {
427 DBG3("UST app send stream to ust failed. Application is dead.");
428 }
429 goto error;
430 }
431 channel->handle = channel->obj->handle;
432
433 error:
434 return ret;
435 }
436
437 /*
438 * Send channel previously received from the consumer to the UST tracer.
439 *
440 * On success return 0 else a negative value.
441 */
442 int ust_consumer_send_channel_to_ust(struct ust_app *app,
443 struct ust_app_session *ua_sess, struct ust_app_channel *channel)
444 {
445 int ret;
446
447 assert(app);
448 assert(ua_sess);
449 assert(channel);
450 assert(channel->obj);
451
452 DBG2("UST app send channel to sock %d pid %d (name: %s, key: %" PRIu64 ")",
453 app->sock, app->pid, channel->name, channel->tracing_channel_id);
454
455 /* Send stream to application. */
456 pthread_mutex_lock(&app->sock_lock);
457 ret = ustctl_send_channel_to_ust(app->sock, ua_sess->handle, channel->obj);
458 pthread_mutex_unlock(&app->sock_lock);
459 if (ret < 0) {
460 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
461 ERR("Error ustctl send channel %s to app pid: %d with ret %d",
462 channel->name, app->pid, ret);
463 } else {
464 DBG3("UST app send channel to ust failed. Application is dead.");
465 }
466 goto error;
467 }
468
469 error:
470 return ret;
471 }
472
473 /*
474 * Handle the metadata requests from the UST consumer
475 *
476 * Return 0 on success else a negative value.
477 */
478 int ust_consumer_metadata_request(struct consumer_socket *socket)
479 {
480 int ret;
481 ssize_t ret_push;
482 struct lttcomm_metadata_request_msg request;
483 struct buffer_reg_uid *reg_uid;
484 struct ust_registry_session *ust_reg;
485 struct lttcomm_consumer_msg msg;
486
487 assert(socket);
488
489 rcu_read_lock();
490 health_code_update();
491
492 /* Wait for a metadata request */
493 pthread_mutex_lock(socket->lock);
494 ret = consumer_socket_recv(socket, &request, sizeof(request));
495 pthread_mutex_unlock(socket->lock);
496 if (ret < 0) {
497 goto end;
498 }
499
500 DBG("Metadata request received for session %" PRIu64 ", key %" PRIu64,
501 request.session_id, request.key);
502
503 reg_uid = buffer_reg_uid_find(request.session_id,
504 request.bits_per_long, request.uid);
505 if (reg_uid) {
506 ust_reg = reg_uid->registry->reg.ust;
507 } else {
508 struct buffer_reg_pid *reg_pid =
509 buffer_reg_pid_find(request.session_id_per_pid);
510 if (!reg_pid) {
511 DBG("PID registry not found for session id %" PRIu64,
512 request.session_id_per_pid);
513
514 memset(&msg, 0, sizeof(msg));
515 msg.cmd_type = LTTNG_ERR_UND;
516 (void) consumer_send_msg(socket, &msg);
517 /*
518 * This is possible since the session might have been destroyed
519 * during a consumer metadata request. So here, return gracefully
520 * because the destroy session will push the remaining metadata to
521 * the consumer.
522 */
523 ret = 0;
524 goto end;
525 }
526 ust_reg = reg_pid->registry->reg.ust;
527 }
528 assert(ust_reg);
529
530 pthread_mutex_lock(&ust_reg->lock);
531 ret_push = ust_app_push_metadata(ust_reg, socket, 1);
532 pthread_mutex_unlock(&ust_reg->lock);
533 if (ret_push == -EPIPE) {
534 DBG("Application or relay closed while pushing metadata");
535 } else if (ret_push < 0) {
536 ERR("Pushing metadata");
537 ret = -1;
538 goto end;
539 } else {
540 DBG("UST Consumer metadata pushed successfully");
541 }
542 ret = 0;
543
544 end:
545 rcu_read_unlock();
546 return ret;
547 }
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