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