Update maintainer section of the man pages
[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-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 (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, 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
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 switch (ua_chan->attr.output) {
145 case LTTNG_UST_MMAP:
146 default:
147 output = LTTNG_EVENT_MMAP;
148 break;
149 }
150
151 consumer_init_ask_channel_comm_msg(&msg,
152 ua_chan->attr.subbuf_size,
153 ua_chan->attr.num_subbuf,
154 ua_chan->attr.overwrite,
155 ua_chan->attr.switch_timer_interval,
156 ua_chan->attr.read_timer_interval,
157 ua_sess->live_timer_interval,
158 output,
159 (int) ua_chan->attr.type,
160 ua_sess->tracing_id,
161 pathname,
162 ua_chan->name,
163 ua_sess->euid,
164 ua_sess->egid,
165 consumer->net_seq_index,
166 ua_chan->key,
167 registry->uuid,
168 chan_id,
169 ua_chan->tracefile_size,
170 ua_chan->tracefile_count,
171 ua_sess->id,
172 ua_sess->output_traces,
173 ua_sess->uid);
174
175 health_code_update();
176
177 ret = consumer_socket_send(socket, &msg, sizeof(msg));
178 if (ret < 0) {
179 goto error;
180 }
181
182 ret = consumer_recv_status_channel(socket, &key,
183 &ua_chan->expected_stream_count);
184 if (ret < 0) {
185 goto error;
186 }
187 /* Communication protocol error. */
188 assert(key == ua_chan->key);
189 /* We need at least one where 1 stream for 1 cpu. */
190 if (ua_sess->output_traces) {
191 assert(ua_chan->expected_stream_count > 0);
192 }
193
194 DBG2("UST ask channel %" PRIu64 " successfully done with %u stream(s)", key,
195 ua_chan->expected_stream_count);
196
197 error:
198 free(pathname);
199 health_code_update();
200 return ret;
201 }
202
203 /*
204 * Ask consumer to create a channel for a given session.
205 *
206 * Returns 0 on success else a negative value.
207 */
208 int ust_consumer_ask_channel(struct ust_app_session *ua_sess,
209 struct ust_app_channel *ua_chan, struct consumer_output *consumer,
210 struct consumer_socket *socket, struct ust_registry_session *registry)
211 {
212 int ret;
213
214 assert(ua_sess);
215 assert(ua_chan);
216 assert(consumer);
217 assert(socket);
218 assert(registry);
219
220 if (!consumer->enabled) {
221 ret = -LTTNG_ERR_NO_CONSUMER;
222 DBG3("Consumer is disabled");
223 goto error;
224 }
225
226 pthread_mutex_lock(socket->lock);
227
228 ret = ask_channel_creation(ua_sess, ua_chan, consumer, socket, registry);
229 if (ret < 0) {
230 goto error;
231 }
232
233 error:
234 pthread_mutex_unlock(socket->lock);
235 return ret;
236 }
237
238 /*
239 * Send a get channel command to consumer using the given channel key. The
240 * channel object is populated and the stream list.
241 *
242 * Return 0 on success else a negative value.
243 */
244 int ust_consumer_get_channel(struct consumer_socket *socket,
245 struct ust_app_channel *ua_chan)
246 {
247 int ret;
248 struct lttcomm_consumer_msg msg;
249
250 assert(ua_chan);
251 assert(socket);
252
253 memset(&msg, 0, sizeof(msg));
254 msg.cmd_type = LTTNG_CONSUMER_GET_CHANNEL;
255 msg.u.get_channel.key = ua_chan->key;
256
257 pthread_mutex_lock(socket->lock);
258 health_code_update();
259
260 /* Send command and wait for OK reply. */
261 ret = consumer_send_msg(socket, &msg);
262 if (ret < 0) {
263 goto error;
264 }
265
266 /* First, get the channel from consumer. */
267 ret = ustctl_recv_channel_from_consumer(*socket->fd_ptr, &ua_chan->obj);
268 if (ret < 0) {
269 if (ret != -EPIPE) {
270 ERR("Error recv channel from consumer %d with ret %d",
271 *socket->fd_ptr, ret);
272 } else {
273 DBG3("UST app recv channel from consumer. Consumer is dead.");
274 }
275 goto error;
276 }
277
278 /* Next, get all streams. */
279 while (1) {
280 struct ust_app_stream *stream;
281
282 /* Create UST stream */
283 stream = ust_app_alloc_stream();
284 if (stream == NULL) {
285 ret = -ENOMEM;
286 goto error;
287 }
288
289 /* Stream object is populated by this call if successful. */
290 ret = ustctl_recv_stream_from_consumer(*socket->fd_ptr, &stream->obj);
291 if (ret < 0) {
292 free(stream);
293 if (ret == -LTTNG_UST_ERR_NOENT) {
294 DBG3("UST app consumer has no more stream available");
295 ret = 0;
296 break;
297 }
298 if (ret != -EPIPE) {
299 ERR("Recv stream from consumer %d with ret %d",
300 *socket->fd_ptr, ret);
301 } else {
302 DBG3("UST app recv stream from consumer. Consumer is dead.");
303 }
304 goto error;
305 }
306
307 /* Order is important this is why a list is used. */
308 cds_list_add_tail(&stream->list, &ua_chan->streams.head);
309 ua_chan->streams.count++;
310
311 DBG2("UST app stream %d received successfully", ua_chan->streams.count);
312 }
313
314 /* This MUST match or else we have a synchronization problem. */
315 assert(ua_chan->expected_stream_count == ua_chan->streams.count);
316
317 /* Wait for confirmation that we can proceed with the streams. */
318 ret = consumer_recv_status_reply(socket);
319 if (ret < 0) {
320 goto error;
321 }
322
323 error:
324 health_code_update();
325 pthread_mutex_unlock(socket->lock);
326 return ret;
327 }
328
329 /*
330 * Send a destroy channel command to consumer using the given channel key.
331 *
332 * Note that this command MUST be used prior to a successful
333 * LTTNG_CONSUMER_GET_CHANNEL because once this command is done successfully,
334 * the streams are dispatched to the consumer threads and MUST be teardown
335 * through the hang up process.
336 *
337 * Return 0 on success else a negative value.
338 */
339 int ust_consumer_destroy_channel(struct consumer_socket *socket,
340 struct ust_app_channel *ua_chan)
341 {
342 int ret;
343 struct lttcomm_consumer_msg msg;
344
345 assert(ua_chan);
346 assert(socket);
347
348 memset(&msg, 0, sizeof(msg));
349 msg.cmd_type = LTTNG_CONSUMER_DESTROY_CHANNEL;
350 msg.u.destroy_channel.key = ua_chan->key;
351
352 pthread_mutex_lock(socket->lock);
353 health_code_update();
354
355 ret = consumer_send_msg(socket, &msg);
356 if (ret < 0) {
357 goto error;
358 }
359
360 error:
361 health_code_update();
362 pthread_mutex_unlock(socket->lock);
363 return ret;
364 }
365
366 /*
367 * Send a given stream to UST tracer.
368 *
369 * On success return 0 else a negative value.
370 */
371 int ust_consumer_send_stream_to_ust(struct ust_app *app,
372 struct ust_app_channel *channel, struct ust_app_stream *stream)
373 {
374 int ret;
375
376 assert(app);
377 assert(stream);
378 assert(channel);
379
380 DBG2("UST consumer send stream to app %d", app->sock);
381
382 /* Relay stream to application. */
383 ret = ustctl_send_stream_to_ust(app->sock, channel->obj, stream->obj);
384 if (ret < 0) {
385 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
386 ERR("ustctl send stream handle %d to app pid: %d with ret %d",
387 stream->obj->handle, app->pid, ret);
388 } else {
389 DBG3("UST app send stream to ust failed. Application is dead.");
390 }
391 goto error;
392 }
393 channel->handle = channel->obj->handle;
394
395 error:
396 return ret;
397 }
398
399 /*
400 * Send channel previously received from the consumer to the UST tracer.
401 *
402 * On success return 0 else a negative value.
403 */
404 int ust_consumer_send_channel_to_ust(struct ust_app *app,
405 struct ust_app_session *ua_sess, struct ust_app_channel *channel)
406 {
407 int ret;
408
409 assert(app);
410 assert(ua_sess);
411 assert(channel);
412 assert(channel->obj);
413
414 DBG2("UST app send channel to sock %d pid %d (name: %s, key: %" PRIu64 ")",
415 app->sock, app->pid, channel->name, channel->tracing_channel_id);
416
417 /* Send stream to application. */
418 ret = ustctl_send_channel_to_ust(app->sock, ua_sess->handle, channel->obj);
419 if (ret < 0) {
420 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
421 ERR("Error ustctl send channel %s to app pid: %d with ret %d",
422 channel->name, app->pid, ret);
423 } else {
424 DBG3("UST app send channel to ust failed. Application is dead.");
425 }
426 goto error;
427 }
428
429 error:
430 return ret;
431 }
432
433 /*
434 * Handle the metadata requests from the UST consumer
435 *
436 * Return 0 on success else a negative value.
437 */
438 int ust_consumer_metadata_request(struct consumer_socket *socket)
439 {
440 int ret;
441 ssize_t ret_push;
442 struct lttcomm_metadata_request_msg request;
443 struct buffer_reg_uid *reg_uid;
444 struct ust_registry_session *ust_reg;
445 struct lttcomm_consumer_msg msg;
446
447 assert(socket);
448
449 rcu_read_lock();
450 pthread_mutex_lock(socket->lock);
451
452 health_code_update();
453
454 /* Wait for a metadata request */
455 ret = consumer_socket_recv(socket, &request, sizeof(request));
456 if (ret < 0) {
457 goto end;
458 }
459
460 DBG("Metadata request received for session %" PRIu64 ", key %" PRIu64,
461 request.session_id, request.key);
462
463 reg_uid = buffer_reg_uid_find(request.session_id,
464 request.bits_per_long, request.uid);
465 if (reg_uid) {
466 ust_reg = reg_uid->registry->reg.ust;
467 } else {
468 struct buffer_reg_pid *reg_pid =
469 buffer_reg_pid_find(request.session_id_per_pid);
470 if (!reg_pid) {
471 DBG("PID registry not found for session id %" PRIu64,
472 request.session_id_per_pid);
473
474 memset(&msg, 0, sizeof(msg));
475 msg.cmd_type = LTTNG_ERR_UND;
476 (void) consumer_send_msg(socket, &msg);
477 /*
478 * This is possible since the session might have been destroyed
479 * during a consumer metadata request. So here, return gracefully
480 * because the destroy session will push the remaining metadata to
481 * the consumer.
482 */
483 ret = 0;
484 goto end;
485 }
486 ust_reg = reg_pid->registry->reg.ust;
487 }
488 assert(ust_reg);
489
490 ret_push = ust_app_push_metadata(ust_reg, socket, 1);
491 if (ret_push < 0) {
492 ERR("Pushing metadata");
493 ret = -1;
494 goto end;
495 }
496 DBG("UST Consumer metadata pushed successfully");
497 ret = 0;
498
499 end:
500 pthread_mutex_unlock(socket->lock);
501 rcu_read_unlock();
502 return ret;
503 }
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