Remove unused ltt_session look-up result
[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
247 assert(ua_sess);
248 assert(ua_chan);
249 assert(consumer);
250 assert(socket);
251 assert(registry);
252
253 if (!consumer->enabled) {
254 ret = -LTTNG_ERR_NO_CONSUMER;
255 DBG3("Consumer is disabled");
256 goto error;
257 }
258
259 pthread_mutex_lock(socket->lock);
260 ret = ask_channel_creation(ua_sess, ua_chan, consumer, socket, registry);
261 pthread_mutex_unlock(socket->lock);
262 if (ret < 0) {
263 ERR("ask_channel_creation consumer command failed");
264 goto error;
265 }
266
267 error:
268 return ret;
269 }
270
271 /*
272 * Send a get channel command to consumer using the given channel key. The
273 * channel object is populated and the stream list.
274 *
275 * Return 0 on success else a negative value.
276 */
277 int ust_consumer_get_channel(struct consumer_socket *socket,
278 struct ust_app_channel *ua_chan)
279 {
280 int ret;
281 struct lttcomm_consumer_msg msg;
282
283 assert(ua_chan);
284 assert(socket);
285
286 memset(&msg, 0, sizeof(msg));
287 msg.cmd_type = LTTNG_CONSUMER_GET_CHANNEL;
288 msg.u.get_channel.key = ua_chan->key;
289
290 pthread_mutex_lock(socket->lock);
291 health_code_update();
292
293 /* Send command and wait for OK reply. */
294 ret = consumer_send_msg(socket, &msg);
295 if (ret < 0) {
296 goto error;
297 }
298
299 /* First, get the channel from consumer. */
300 ret = ustctl_recv_channel_from_consumer(*socket->fd_ptr, &ua_chan->obj);
301 if (ret < 0) {
302 if (ret != -EPIPE) {
303 ERR("Error recv channel from consumer %d with ret %d",
304 *socket->fd_ptr, ret);
305 } else {
306 DBG3("UST app recv channel from consumer. Consumer is dead.");
307 }
308 goto error;
309 }
310
311 /* Next, get all streams. */
312 while (1) {
313 struct ust_app_stream *stream;
314
315 /* Create UST stream */
316 stream = ust_app_alloc_stream();
317 if (stream == NULL) {
318 ret = -ENOMEM;
319 goto error;
320 }
321
322 /* Stream object is populated by this call if successful. */
323 ret = ustctl_recv_stream_from_consumer(*socket->fd_ptr, &stream->obj);
324 if (ret < 0) {
325 free(stream);
326 if (ret == -LTTNG_UST_ERR_NOENT) {
327 DBG3("UST app consumer has no more stream available");
328 break;
329 }
330 if (ret != -EPIPE) {
331 ERR("Recv stream from consumer %d with ret %d",
332 *socket->fd_ptr, ret);
333 } else {
334 DBG3("UST app recv stream from consumer. Consumer is dead.");
335 }
336 goto error;
337 }
338
339 /* Order is important this is why a list is used. */
340 cds_list_add_tail(&stream->list, &ua_chan->streams.head);
341 ua_chan->streams.count++;
342
343 DBG2("UST app stream %d received successfully", ua_chan->streams.count);
344 }
345
346 /* This MUST match or else we have a synchronization problem. */
347 assert(ua_chan->expected_stream_count == ua_chan->streams.count);
348
349 /* Wait for confirmation that we can proceed with the streams. */
350 ret = consumer_recv_status_reply(socket);
351 if (ret < 0) {
352 goto error;
353 }
354
355 error:
356 health_code_update();
357 pthread_mutex_unlock(socket->lock);
358 return ret;
359 }
360
361 /*
362 * Send a destroy channel command to consumer using the given channel key.
363 *
364 * Note that this command MUST be used prior to a successful
365 * LTTNG_CONSUMER_GET_CHANNEL because once this command is done successfully,
366 * the streams are dispatched to the consumer threads and MUST be teardown
367 * through the hang up process.
368 *
369 * Return 0 on success else a negative value.
370 */
371 int ust_consumer_destroy_channel(struct consumer_socket *socket,
372 struct ust_app_channel *ua_chan)
373 {
374 int ret;
375 struct lttcomm_consumer_msg msg;
376
377 assert(ua_chan);
378 assert(socket);
379
380 memset(&msg, 0, sizeof(msg));
381 msg.cmd_type = LTTNG_CONSUMER_DESTROY_CHANNEL;
382 msg.u.destroy_channel.key = ua_chan->key;
383
384 pthread_mutex_lock(socket->lock);
385 health_code_update();
386
387 ret = consumer_send_msg(socket, &msg);
388 if (ret < 0) {
389 goto error;
390 }
391
392 error:
393 health_code_update();
394 pthread_mutex_unlock(socket->lock);
395 return ret;
396 }
397
398 /*
399 * Send a given stream to UST tracer.
400 *
401 * On success return 0 else a negative value.
402 */
403 int ust_consumer_send_stream_to_ust(struct ust_app *app,
404 struct ust_app_channel *channel, struct ust_app_stream *stream)
405 {
406 int ret;
407
408 assert(app);
409 assert(stream);
410 assert(channel);
411
412 DBG2("UST consumer send stream to app %d", app->sock);
413
414 /* Relay stream to application. */
415 pthread_mutex_lock(&app->sock_lock);
416 ret = ustctl_send_stream_to_ust(app->sock, channel->obj, stream->obj);
417 pthread_mutex_unlock(&app->sock_lock);
418 if (ret < 0) {
419 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
420 ERR("ustctl send stream handle %d to app pid: %d with ret %d",
421 stream->obj->handle, app->pid, ret);
422 } else {
423 DBG3("UST app send stream to ust failed. Application is dead.");
424 }
425 goto error;
426 }
427 channel->handle = channel->obj->handle;
428
429 error:
430 return ret;
431 }
432
433 /*
434 * Send channel previously received from the consumer to the UST tracer.
435 *
436 * On success return 0 else a negative value.
437 */
438 int ust_consumer_send_channel_to_ust(struct ust_app *app,
439 struct ust_app_session *ua_sess, struct ust_app_channel *channel)
440 {
441 int ret;
442
443 assert(app);
444 assert(ua_sess);
445 assert(channel);
446 assert(channel->obj);
447
448 DBG2("UST app send channel to sock %d pid %d (name: %s, key: %" PRIu64 ")",
449 app->sock, app->pid, channel->name, channel->tracing_channel_id);
450
451 /* Send stream to application. */
452 pthread_mutex_lock(&app->sock_lock);
453 ret = ustctl_send_channel_to_ust(app->sock, ua_sess->handle, channel->obj);
454 pthread_mutex_unlock(&app->sock_lock);
455 if (ret < 0) {
456 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
457 ERR("Error ustctl send channel %s to app pid: %d with ret %d",
458 channel->name, app->pid, ret);
459 } else {
460 DBG3("UST app send channel to ust failed. Application is dead.");
461 }
462 goto error;
463 }
464
465 error:
466 return ret;
467 }
468
469 /*
470 * Handle the metadata requests from the UST consumer
471 *
472 * Return 0 on success else a negative value.
473 */
474 int ust_consumer_metadata_request(struct consumer_socket *socket)
475 {
476 int ret;
477 ssize_t ret_push;
478 struct lttcomm_metadata_request_msg request;
479 struct buffer_reg_uid *reg_uid;
480 struct ust_registry_session *ust_reg;
481 struct lttcomm_consumer_msg msg;
482
483 assert(socket);
484
485 rcu_read_lock();
486 health_code_update();
487
488 /* Wait for a metadata request */
489 pthread_mutex_lock(socket->lock);
490 ret = consumer_socket_recv(socket, &request, sizeof(request));
491 pthread_mutex_unlock(socket->lock);
492 if (ret < 0) {
493 goto end;
494 }
495
496 DBG("Metadata request received for session %" PRIu64 ", key %" PRIu64,
497 request.session_id, request.key);
498
499 reg_uid = buffer_reg_uid_find(request.session_id,
500 request.bits_per_long, request.uid);
501 if (reg_uid) {
502 ust_reg = reg_uid->registry->reg.ust;
503 } else {
504 struct buffer_reg_pid *reg_pid =
505 buffer_reg_pid_find(request.session_id_per_pid);
506 if (!reg_pid) {
507 DBG("PID registry not found for session id %" PRIu64,
508 request.session_id_per_pid);
509
510 memset(&msg, 0, sizeof(msg));
511 msg.cmd_type = LTTNG_ERR_UND;
512 pthread_mutex_lock(socket->lock);
513 (void) consumer_send_msg(socket, &msg);
514 pthread_mutex_unlock(socket->lock);
515 /*
516 * This is possible since the session might have been destroyed
517 * during a consumer metadata request. So here, return gracefully
518 * because the destroy session will push the remaining metadata to
519 * the consumer.
520 */
521 ret = 0;
522 goto end;
523 }
524 ust_reg = reg_pid->registry->reg.ust;
525 }
526 assert(ust_reg);
527
528 pthread_mutex_lock(&ust_reg->lock);
529 ret_push = ust_app_push_metadata(ust_reg, socket, 1);
530 pthread_mutex_unlock(&ust_reg->lock);
531 if (ret_push == -EPIPE) {
532 DBG("Application or relay closed while pushing metadata");
533 } else if (ret_push < 0) {
534 ERR("Pushing metadata");
535 ret = -1;
536 goto end;
537 } else {
538 DBG("UST Consumer metadata pushed successfully");
539 }
540 ret = 0;
541
542 end:
543 rcu_read_unlock();
544 return ret;
545 }
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