ba464d9b7d90c8b1a318c527eefaf7f5032b2b02
[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 #define _LGPL_SOURCE
20 #include <errno.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <unistd.h>
25 #include <inttypes.h>
26
27 #include <common/common.h>
28 #include <common/consumer.h>
29 #include <common/defaults.h>
30
31 #include "consumer.h"
32 #include "health-sessiond.h"
33 #include "ust-consumer.h"
34 #include "buffer-registry.h"
35 #include "session.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 (ret != -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 ADD_CHANNEL.
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 output,
179 (int) ua_chan->attr.type,
180 ua_sess->tracing_id,
181 pathname,
182 ua_chan->name,
183 ua_sess->euid,
184 ua_sess->egid,
185 consumer->net_seq_index,
186 ua_chan->key,
187 registry->uuid,
188 chan_id,
189 ua_chan->tracefile_size,
190 ua_chan->tracefile_count,
191 ua_sess->id,
192 ua_sess->output_traces,
193 ua_sess->uid,
194 root_shm_path, shm_path);
195
196 health_code_update();
197
198 ret = consumer_socket_send(socket, &msg, sizeof(msg));
199 if (ret < 0) {
200 goto error;
201 }
202
203 ret = consumer_recv_status_channel(socket, &key,
204 &ua_chan->expected_stream_count);
205 if (ret < 0) {
206 goto error;
207 }
208 /* Communication protocol error. */
209 assert(key == ua_chan->key);
210 /* We need at least one where 1 stream for 1 cpu. */
211 if (ua_sess->output_traces) {
212 assert(ua_chan->expected_stream_count > 0);
213 }
214
215 DBG2("UST ask channel %" PRIu64 " successfully done with %u stream(s)", key,
216 ua_chan->expected_stream_count);
217
218 error:
219 free(pathname);
220 health_code_update();
221 return ret;
222 }
223
224 /*
225 * Ask consumer to create a channel for a given session.
226 *
227 * Returns 0 on success else a negative value.
228 */
229 int ust_consumer_ask_channel(struct ust_app_session *ua_sess,
230 struct ust_app_channel *ua_chan, struct consumer_output *consumer,
231 struct consumer_socket *socket, struct ust_registry_session *registry)
232 {
233 int ret;
234
235 assert(ua_sess);
236 assert(ua_chan);
237 assert(consumer);
238 assert(socket);
239 assert(registry);
240
241 if (!consumer->enabled) {
242 ret = -LTTNG_ERR_NO_CONSUMER;
243 DBG3("Consumer is disabled");
244 goto error;
245 }
246
247 pthread_mutex_lock(socket->lock);
248 ret = ask_channel_creation(ua_sess, ua_chan, consumer, socket, registry);
249 pthread_mutex_unlock(socket->lock);
250 if (ret < 0) {
251 goto error;
252 }
253
254 error:
255 return ret;
256 }
257
258 /*
259 * Send a get channel command to consumer using the given channel key. The
260 * channel object is populated and the stream list.
261 *
262 * Return 0 on success else a negative value.
263 */
264 int ust_consumer_get_channel(struct consumer_socket *socket,
265 struct ust_app_channel *ua_chan)
266 {
267 int ret;
268 struct lttcomm_consumer_msg msg;
269
270 assert(ua_chan);
271 assert(socket);
272
273 memset(&msg, 0, sizeof(msg));
274 msg.cmd_type = LTTNG_CONSUMER_GET_CHANNEL;
275 msg.u.get_channel.key = ua_chan->key;
276
277 pthread_mutex_lock(socket->lock);
278 health_code_update();
279
280 /* Send command and wait for OK reply. */
281 ret = consumer_send_msg(socket, &msg);
282 if (ret < 0) {
283 goto error;
284 }
285
286 /* First, get the channel from consumer. */
287 ret = ustctl_recv_channel_from_consumer(*socket->fd_ptr, &ua_chan->obj);
288 if (ret < 0) {
289 if (ret != -EPIPE) {
290 ERR("Error recv channel from consumer %d with ret %d",
291 *socket->fd_ptr, ret);
292 } else {
293 DBG3("UST app recv channel from consumer. Consumer is dead.");
294 }
295 goto error;
296 }
297
298 /* Next, get all streams. */
299 while (1) {
300 struct ust_app_stream *stream;
301
302 /* Create UST stream */
303 stream = ust_app_alloc_stream();
304 if (stream == NULL) {
305 ret = -ENOMEM;
306 goto error;
307 }
308
309 /* Stream object is populated by this call if successful. */
310 ret = ustctl_recv_stream_from_consumer(*socket->fd_ptr, &stream->obj);
311 if (ret < 0) {
312 free(stream);
313 if (ret == -LTTNG_UST_ERR_NOENT) {
314 DBG3("UST app consumer has no more stream available");
315 ret = 0;
316 break;
317 }
318 if (ret != -EPIPE) {
319 ERR("Recv stream from consumer %d with ret %d",
320 *socket->fd_ptr, ret);
321 } else {
322 DBG3("UST app recv stream from consumer. Consumer is dead.");
323 }
324 goto error;
325 }
326
327 /* Order is important this is why a list is used. */
328 cds_list_add_tail(&stream->list, &ua_chan->streams.head);
329 ua_chan->streams.count++;
330
331 DBG2("UST app stream %d received successfully", ua_chan->streams.count);
332 }
333
334 /* This MUST match or else we have a synchronization problem. */
335 assert(ua_chan->expected_stream_count == ua_chan->streams.count);
336
337 /* Wait for confirmation that we can proceed with the streams. */
338 ret = consumer_recv_status_reply(socket);
339 if (ret < 0) {
340 goto error;
341 }
342
343 error:
344 health_code_update();
345 pthread_mutex_unlock(socket->lock);
346 return ret;
347 }
348
349 /*
350 * Send a destroy channel command to consumer using the given channel key.
351 *
352 * Note that this command MUST be used prior to a successful
353 * LTTNG_CONSUMER_GET_CHANNEL because once this command is done successfully,
354 * the streams are dispatched to the consumer threads and MUST be teardown
355 * through the hang up process.
356 *
357 * Return 0 on success else a negative value.
358 */
359 int ust_consumer_destroy_channel(struct consumer_socket *socket,
360 struct ust_app_channel *ua_chan)
361 {
362 int ret;
363 struct lttcomm_consumer_msg msg;
364
365 assert(ua_chan);
366 assert(socket);
367
368 memset(&msg, 0, sizeof(msg));
369 msg.cmd_type = LTTNG_CONSUMER_DESTROY_CHANNEL;
370 msg.u.destroy_channel.key = ua_chan->key;
371
372 pthread_mutex_lock(socket->lock);
373 health_code_update();
374
375 ret = consumer_send_msg(socket, &msg);
376 if (ret < 0) {
377 goto error;
378 }
379
380 error:
381 health_code_update();
382 pthread_mutex_unlock(socket->lock);
383 return ret;
384 }
385
386 /*
387 * Send a given stream to UST tracer.
388 *
389 * On success return 0 else a negative value.
390 */
391 int ust_consumer_send_stream_to_ust(struct ust_app *app,
392 struct ust_app_channel *channel, struct ust_app_stream *stream)
393 {
394 int ret;
395
396 assert(app);
397 assert(stream);
398 assert(channel);
399
400 DBG2("UST consumer send stream to app %d", app->sock);
401
402 /* Relay stream to application. */
403 ret = ustctl_send_stream_to_ust(app->sock, channel->obj, stream->obj);
404 if (ret < 0) {
405 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
406 ERR("ustctl send stream handle %d to app pid: %d with ret %d",
407 stream->obj->handle, app->pid, ret);
408 } else {
409 DBG3("UST app send stream to ust failed. Application is dead.");
410 }
411 goto error;
412 }
413 channel->handle = channel->obj->handle;
414
415 error:
416 return ret;
417 }
418
419 /*
420 * Send channel previously received from the consumer to the UST tracer.
421 *
422 * On success return 0 else a negative value.
423 */
424 int ust_consumer_send_channel_to_ust(struct ust_app *app,
425 struct ust_app_session *ua_sess, struct ust_app_channel *channel)
426 {
427 int ret;
428
429 assert(app);
430 assert(ua_sess);
431 assert(channel);
432 assert(channel->obj);
433
434 DBG2("UST app send channel to sock %d pid %d (name: %s, key: %" PRIu64 ")",
435 app->sock, app->pid, channel->name, channel->tracing_channel_id);
436
437 /* Send stream to application. */
438 ret = ustctl_send_channel_to_ust(app->sock, ua_sess->handle, channel->obj);
439 if (ret < 0) {
440 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
441 ERR("Error ustctl send channel %s to app pid: %d with ret %d",
442 channel->name, app->pid, ret);
443 } else {
444 DBG3("UST app send channel to ust failed. Application is dead.");
445 }
446 goto error;
447 }
448
449 error:
450 return ret;
451 }
452
453 /*
454 * Handle the metadata requests from the UST consumer
455 *
456 * Return 0 on success else a negative value.
457 */
458 int ust_consumer_metadata_request(struct consumer_socket *socket)
459 {
460 int ret;
461 ssize_t ret_push;
462 struct lttcomm_metadata_request_msg request;
463 struct buffer_reg_uid *reg_uid;
464 struct ust_registry_session *ust_reg;
465 struct lttcomm_consumer_msg msg;
466
467 assert(socket);
468
469 rcu_read_lock();
470 health_code_update();
471
472 /* Wait for a metadata request */
473 pthread_mutex_lock(socket->lock);
474 ret = consumer_socket_recv(socket, &request, sizeof(request));
475 pthread_mutex_unlock(socket->lock);
476 if (ret < 0) {
477 goto end;
478 }
479
480 DBG("Metadata request received for session %" PRIu64 ", key %" PRIu64,
481 request.session_id, request.key);
482
483 reg_uid = buffer_reg_uid_find(request.session_id,
484 request.bits_per_long, request.uid);
485 if (reg_uid) {
486 ust_reg = reg_uid->registry->reg.ust;
487 } else {
488 struct buffer_reg_pid *reg_pid =
489 buffer_reg_pid_find(request.session_id_per_pid);
490 if (!reg_pid) {
491 DBG("PID registry not found for session id %" PRIu64,
492 request.session_id_per_pid);
493
494 memset(&msg, 0, sizeof(msg));
495 msg.cmd_type = LTTNG_ERR_UND;
496 (void) consumer_send_msg(socket, &msg);
497 /*
498 * This is possible since the session might have been destroyed
499 * during a consumer metadata request. So here, return gracefully
500 * because the destroy session will push the remaining metadata to
501 * the consumer.
502 */
503 ret = 0;
504 goto end;
505 }
506 ust_reg = reg_pid->registry->reg.ust;
507 }
508 assert(ust_reg);
509
510 pthread_mutex_lock(&ust_reg->lock);
511 ret_push = ust_app_push_metadata(ust_reg, socket, 1);
512 pthread_mutex_unlock(&ust_reg->lock);
513 if (ret_push == -EPIPE) {
514 DBG("Application or relay closed while pushing metadata");
515 } else if (ret_push < 0) {
516 ERR("Pushing metadata");
517 ret = -1;
518 goto end;
519 } else {
520 DBG("UST Consumer metadata pushed successfully");
521 }
522 ret = 0;
523
524 end:
525 rcu_read_unlock();
526 return ret;
527 }
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