Introduce configure --with-lttng-system-rundir
[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 _GNU_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.h>
28 #include <common/defaults.h>
29
30 #include "consumer.h"
31 #include "health.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 (ret != -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;
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
112 assert(ua_sess);
113 assert(ua_chan);
114 assert(socket);
115 assert(consumer);
116 assert(registry);
117
118 DBG2("Asking UST consumer for channel");
119
120 /* Get and create full trace path of session. */
121 if (ua_sess->output_traces) {
122 pathname = setup_trace_path(consumer, ua_sess);
123 if (!pathname) {
124 ret = -1;
125 goto error;
126 }
127 }
128
129 /* Depending on the buffer type, a different channel key is used. */
130 if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
131 chan_reg_key = ua_chan->tracing_channel_id;
132 } else {
133 chan_reg_key = ua_chan->key;
134 }
135
136 if (ua_chan->attr.type == LTTNG_UST_CHAN_METADATA) {
137 chan_id = -1U;
138 } else {
139 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
140 assert(chan_reg);
141 chan_id = chan_reg->chan_id;
142 }
143
144 consumer_init_ask_channel_comm_msg(&msg,
145 ua_chan->attr.subbuf_size,
146 ua_chan->attr.num_subbuf,
147 ua_chan->attr.overwrite,
148 ua_chan->attr.switch_timer_interval,
149 ua_chan->attr.read_timer_interval,
150 (int) ua_chan->attr.output,
151 (int) ua_chan->attr.type,
152 ua_sess->tracing_id,
153 pathname,
154 ua_chan->name,
155 ua_sess->euid,
156 ua_sess->egid,
157 consumer->net_seq_index,
158 ua_chan->key,
159 registry->uuid,
160 chan_id,
161 ua_chan->tracefile_size,
162 ua_chan->tracefile_count,
163 ua_sess->id,
164 ua_sess->output_traces,
165 ua_sess->uid);
166
167 health_code_update();
168
169 ret = lttcomm_send_unix_sock(socket->fd, &msg, sizeof(msg));
170 if (ret < 0) {
171 goto error;
172 }
173
174 ret = consumer_recv_status_channel(socket, &key,
175 &ua_chan->expected_stream_count);
176 if (ret < 0) {
177 goto error;
178 }
179 /* Communication protocol error. */
180 assert(key == ua_chan->key);
181 /* We need at least one where 1 stream for 1 cpu. */
182 if (ua_sess->output_traces) {
183 assert(ua_chan->expected_stream_count > 0);
184 }
185
186 DBG2("UST ask channel %" PRIu64 " successfully done with %u stream(s)", key,
187 ua_chan->expected_stream_count);
188
189 error:
190 free(pathname);
191 health_code_update();
192 return ret;
193 }
194
195 /*
196 * Ask consumer to create a channel for a given session.
197 *
198 * Returns 0 on success else a negative value.
199 */
200 int ust_consumer_ask_channel(struct ust_app_session *ua_sess,
201 struct ust_app_channel *ua_chan, struct consumer_output *consumer,
202 struct consumer_socket *socket, struct ust_registry_session *registry)
203 {
204 int ret;
205
206 assert(ua_sess);
207 assert(ua_chan);
208 assert(consumer);
209 assert(socket);
210 assert(socket->fd >= 0);
211 assert(registry);
212
213 if (!consumer->enabled) {
214 ret = -LTTNG_ERR_NO_CONSUMER;
215 DBG3("Consumer is disabled");
216 goto error;
217 }
218
219 pthread_mutex_lock(socket->lock);
220
221 ret = ask_channel_creation(ua_sess, ua_chan, consumer, socket, registry);
222 if (ret < 0) {
223 goto error;
224 }
225
226 error:
227 pthread_mutex_unlock(socket->lock);
228 return ret;
229 }
230
231 /*
232 * Send a get channel command to consumer using the given channel key. The
233 * channel object is populated and the stream list.
234 *
235 * Return 0 on success else a negative value.
236 */
237 int ust_consumer_get_channel(struct consumer_socket *socket,
238 struct ust_app_channel *ua_chan)
239 {
240 int ret;
241 struct lttcomm_consumer_msg msg;
242
243 assert(ua_chan);
244 assert(socket);
245 assert(socket->fd >= 0);
246
247 msg.cmd_type = LTTNG_CONSUMER_GET_CHANNEL;
248 msg.u.get_channel.key = ua_chan->key;
249
250 pthread_mutex_lock(socket->lock);
251 health_code_update();
252
253 /* Send command and wait for OK reply. */
254 ret = consumer_send_msg(socket, &msg);
255 if (ret < 0) {
256 goto error;
257 }
258
259 /* First, get the channel from consumer. */
260 ret = ustctl_recv_channel_from_consumer(socket->fd, &ua_chan->obj);
261 if (ret < 0) {
262 if (ret != -EPIPE) {
263 ERR("Error recv channel from consumer %d with ret %d",
264 socket->fd, ret);
265 } else {
266 DBG3("UST app recv channel from consumer. Consumer is dead.");
267 }
268 goto error;
269 }
270
271 /* Next, get all streams. */
272 while (1) {
273 struct ust_app_stream *stream;
274
275 /* Create UST stream */
276 stream = ust_app_alloc_stream();
277 if (stream == NULL) {
278 ret = -ENOMEM;
279 goto error;
280 }
281
282 /* Stream object is populated by this call if successful. */
283 ret = ustctl_recv_stream_from_consumer(socket->fd, &stream->obj);
284 if (ret < 0) {
285 free(stream);
286 if (ret == -LTTNG_UST_ERR_NOENT) {
287 DBG3("UST app consumer has no more stream available");
288 ret = 0;
289 break;
290 }
291 if (ret != -EPIPE) {
292 ERR("Recv stream from consumer %d with ret %d",
293 socket->fd, ret);
294 } else {
295 DBG3("UST app recv stream from consumer. Consumer is dead.");
296 }
297 goto error;
298 }
299
300 /* Order is important this is why a list is used. */
301 cds_list_add_tail(&stream->list, &ua_chan->streams.head);
302 ua_chan->streams.count++;
303
304 DBG2("UST app stream %d received succesfully", ua_chan->streams.count);
305 }
306
307 /* This MUST match or else we have a synchronization problem. */
308 assert(ua_chan->expected_stream_count == ua_chan->streams.count);
309
310 /* Wait for confirmation that we can proceed with the streams. */
311 ret = consumer_recv_status_reply(socket);
312 if (ret < 0) {
313 goto error;
314 }
315
316 error:
317 health_code_update();
318 pthread_mutex_unlock(socket->lock);
319 return ret;
320 }
321
322 /*
323 * Send a destroy channel command to consumer using the given channel key.
324 *
325 * Note that this command MUST be used prior to a successful
326 * LTTNG_CONSUMER_GET_CHANNEL because once this command is done successfully,
327 * the streams are dispatched to the consumer threads and MUST be teardown
328 * through the hang up process.
329 *
330 * Return 0 on success else a negative value.
331 */
332 int ust_consumer_destroy_channel(struct consumer_socket *socket,
333 struct ust_app_channel *ua_chan)
334 {
335 int ret;
336 struct lttcomm_consumer_msg msg;
337
338 assert(ua_chan);
339 assert(socket);
340 assert(socket->fd >= 0);
341
342 msg.cmd_type = LTTNG_CONSUMER_DESTROY_CHANNEL;
343 msg.u.destroy_channel.key = ua_chan->key;
344
345 pthread_mutex_lock(socket->lock);
346 health_code_update();
347
348 ret = consumer_send_msg(socket, &msg);
349 if (ret < 0) {
350 goto error;
351 }
352
353 error:
354 health_code_update();
355 pthread_mutex_unlock(socket->lock);
356 return ret;
357 }
358
359 /*
360 * Send a given stream to UST tracer.
361 *
362 * On success return 0 else a negative value.
363 */
364 int ust_consumer_send_stream_to_ust(struct ust_app *app,
365 struct ust_app_channel *channel, struct ust_app_stream *stream)
366 {
367 int ret;
368
369 assert(app);
370 assert(stream);
371 assert(channel);
372
373 DBG2("UST consumer send stream to app %d", app->sock);
374
375 /* Relay stream to application. */
376 ret = ustctl_send_stream_to_ust(app->sock, channel->obj, stream->obj);
377 if (ret < 0) {
378 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
379 ERR("Error ustctl send stream %s to app pid: %d with ret %d",
380 stream->name, app->pid, ret);
381 } else {
382 DBG3("UST app send stream to ust failed. Application is dead.");
383 }
384 goto error;
385 }
386 channel->handle = channel->obj->handle;
387
388 error:
389 return ret;
390 }
391
392 /*
393 * Send channel previously received from the consumer to the UST tracer.
394 *
395 * On success return 0 else a negative value.
396 */
397 int ust_consumer_send_channel_to_ust(struct ust_app *app,
398 struct ust_app_session *ua_sess, struct ust_app_channel *channel)
399 {
400 int ret;
401
402 assert(app);
403 assert(ua_sess);
404 assert(channel);
405 assert(channel->obj);
406
407 DBG2("UST app send channel to sock %d pid %d (name: %s, key: %" PRIu64 ")",
408 app->sock, app->pid, channel->name, channel->tracing_channel_id);
409
410 /* Send stream to application. */
411 ret = ustctl_send_channel_to_ust(app->sock, ua_sess->handle, channel->obj);
412 if (ret < 0) {
413 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
414 ERR("Error ustctl send channel %s to app pid: %d with ret %d",
415 channel->name, app->pid, ret);
416 } else {
417 DBG3("UST app send channel to ust failed. Application is dead.");
418 }
419 goto error;
420 }
421
422 error:
423 return ret;
424 }
425
426 /*
427 * Handle the metadata requests from the UST consumer
428 *
429 * Return 0 on success else a negative value.
430 */
431 int ust_consumer_metadata_request(struct consumer_socket *socket)
432 {
433 int ret;
434 ssize_t ret_push;
435 struct lttcomm_metadata_request_msg request;
436 struct buffer_reg_uid *reg_uid;
437 struct ust_registry_session *ust_reg;
438 struct lttcomm_consumer_msg msg;
439
440 assert(socket);
441
442 rcu_read_lock();
443 pthread_mutex_lock(socket->lock);
444
445 health_code_update();
446
447 /* Wait for a metadata request */
448 ret = lttcomm_recv_unix_sock(socket->fd, &request, sizeof(request));
449 if (ret <= 0) {
450 ERR("Consumer closed the metadata socket");
451 ret = -1;
452 goto end;
453 }
454
455 DBG("Metadata request received for session %" PRIu64 ", key %" PRIu64,
456 request.session_id, request.key);
457
458 reg_uid = buffer_reg_uid_find(request.session_id,
459 request.bits_per_long, request.uid);
460 if (reg_uid) {
461 ust_reg = reg_uid->registry->reg.ust;
462 } else {
463 struct buffer_reg_pid *reg_pid =
464 buffer_reg_pid_find(request.session_id_per_pid);
465 if (!reg_pid) {
466 DBG("PID registry not found for session id %" PRIu64,
467 request.session_id_per_pid);
468
469 msg.cmd_type = LTTNG_ERR_UND;
470 (void) consumer_send_msg(socket, &msg);
471 /*
472 * This is possible since the session might have been destroyed
473 * during a consumer metadata request. So here, return gracefully
474 * because the destroy session will push the remaining metadata to
475 * the consumer.
476 */
477 ret = 0;
478 goto end;
479 }
480 ust_reg = reg_pid->registry->reg.ust;
481 }
482 assert(ust_reg);
483
484 ret_push = ust_app_push_metadata(ust_reg, socket, 1);
485 if (ret_push < 0) {
486 ERR("Pushing metadata");
487 ret = -1;
488 goto end;
489 }
490 DBG("UST Consumer metadata pushed successfully");
491 ret = 0;
492
493 end:
494 pthread_mutex_unlock(socket->lock);
495 rcu_read_unlock();
496 return ret;
497 }
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