5aa0cd82b60884782e7a60644c0715e9b8e10176
[lttng-tools.git] / src / bin / lttng-sessiond / channel.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _LGPL_SOURCE
20 #include <inttypes.h>
21 #include <string.h>
22 #include <unistd.h>
23
24 #include <common/common.h>
25 #include <common/defaults.h>
26 #include <common/sessiond-comm/sessiond-comm.h>
27
28 #include "channel.h"
29 #include "lttng-sessiond.h"
30 #include "kernel.h"
31 #include "ust-ctl.h"
32 #include "utils.h"
33 #include "ust-app.h"
34 #include "agent.h"
35
36 /*
37 * Return allocated channel attributes.
38 */
39 struct lttng_channel *channel_new_default_attr(int dom,
40 enum lttng_buffer_type type)
41 {
42 struct lttng_channel *chan;
43 const char *channel_name = DEFAULT_CHANNEL_NAME;
44 struct lttng_channel_extended *extended_attr = NULL;
45
46 chan = zmalloc(sizeof(struct lttng_channel));
47 if (chan == NULL) {
48 PERROR("zmalloc channel init");
49 goto error_alloc;
50 }
51
52 extended_attr = zmalloc(sizeof(struct lttng_channel_extended));
53 if (!extended_attr) {
54 PERROR("zmalloc channel extended init");
55 goto error;
56 }
57
58 chan->attr.extended.ptr = extended_attr;
59
60 /* Same for all domains. */
61 chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
62 chan->attr.tracefile_size = DEFAULT_CHANNEL_TRACEFILE_SIZE;
63 chan->attr.tracefile_count = DEFAULT_CHANNEL_TRACEFILE_COUNT;
64
65 switch (dom) {
66 case LTTNG_DOMAIN_KERNEL:
67 assert(type == LTTNG_BUFFER_GLOBAL);
68 chan->attr.subbuf_size =
69 default_get_kernel_channel_subbuf_size();
70 chan->attr.num_subbuf = DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM;
71 chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
72 chan->attr.switch_timer_interval = DEFAULT_KERNEL_CHANNEL_SWITCH_TIMER;
73 chan->attr.read_timer_interval = DEFAULT_KERNEL_CHANNEL_READ_TIMER;
74 chan->attr.live_timer_interval = DEFAULT_KERNEL_CHANNEL_LIVE_TIMER;
75 extended_attr->blocking_timeout = DEFAULT_KERNEL_CHANNEL_BLOCKING_TIMEOUT;
76 extended_attr->monitor_timer_interval =
77 DEFAULT_KERNEL_CHANNEL_MONITOR_TIMER;
78 break;
79 case LTTNG_DOMAIN_JUL:
80 channel_name = DEFAULT_JUL_CHANNEL_NAME;
81 goto common_ust;
82 case LTTNG_DOMAIN_LOG4J:
83 channel_name = DEFAULT_LOG4J_CHANNEL_NAME;
84 goto common_ust;
85 case LTTNG_DOMAIN_PYTHON:
86 channel_name = DEFAULT_PYTHON_CHANNEL_NAME;
87 goto common_ust;
88 case LTTNG_DOMAIN_UST:
89 common_ust:
90 switch (type) {
91 case LTTNG_BUFFER_PER_UID:
92 chan->attr.subbuf_size = default_get_ust_uid_channel_subbuf_size();
93 chan->attr.num_subbuf = DEFAULT_UST_UID_CHANNEL_SUBBUF_NUM;
94 chan->attr.output = DEFAULT_UST_UID_CHANNEL_OUTPUT;
95 chan->attr.switch_timer_interval =
96 DEFAULT_UST_UID_CHANNEL_SWITCH_TIMER;
97 chan->attr.read_timer_interval =
98 DEFAULT_UST_UID_CHANNEL_READ_TIMER;
99 chan->attr.live_timer_interval =
100 DEFAULT_UST_UID_CHANNEL_LIVE_TIMER;
101 extended_attr->blocking_timeout = DEFAULT_UST_UID_CHANNEL_BLOCKING_TIMEOUT;
102 extended_attr->monitor_timer_interval =
103 DEFAULT_UST_UID_CHANNEL_MONITOR_TIMER;
104 break;
105 case LTTNG_BUFFER_PER_PID:
106 default:
107 chan->attr.subbuf_size = default_get_ust_pid_channel_subbuf_size();
108 chan->attr.num_subbuf = DEFAULT_UST_PID_CHANNEL_SUBBUF_NUM;
109 chan->attr.output = DEFAULT_UST_PID_CHANNEL_OUTPUT;
110 chan->attr.switch_timer_interval =
111 DEFAULT_UST_PID_CHANNEL_SWITCH_TIMER;
112 chan->attr.read_timer_interval =
113 DEFAULT_UST_PID_CHANNEL_READ_TIMER;
114 chan->attr.live_timer_interval =
115 DEFAULT_UST_PID_CHANNEL_LIVE_TIMER;
116 extended_attr->blocking_timeout = DEFAULT_UST_PID_CHANNEL_BLOCKING_TIMEOUT;
117 extended_attr->monitor_timer_interval =
118 DEFAULT_UST_PID_CHANNEL_MONITOR_TIMER;
119 break;
120 }
121 break;
122 default:
123 goto error; /* Not implemented */
124 }
125
126 if (snprintf(chan->name, sizeof(chan->name), "%s",
127 channel_name) < 0) {
128 PERROR("snprintf default channel name");
129 goto error;
130 }
131 return chan;
132
133 error:
134 free(extended_attr);
135 free(chan);
136 error_alloc:
137 return NULL;
138 }
139
140 void channel_attr_destroy(struct lttng_channel *channel)
141 {
142 if (!channel) {
143 return;
144 }
145 free(channel->attr.extended.ptr);
146 free(channel);
147 }
148
149 /*
150 * Disable kernel channel of the kernel session.
151 */
152 int channel_kernel_disable(struct ltt_kernel_session *ksession,
153 char *channel_name)
154 {
155 int ret;
156 struct ltt_kernel_channel *kchan;
157
158 assert(ksession);
159 assert(channel_name);
160
161 kchan = trace_kernel_get_channel_by_name(channel_name, ksession);
162 if (kchan == NULL) {
163 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
164 goto error;
165 }
166
167 /* Only if channel is enabled disable it. */
168 if (kchan->enabled == 1) {
169 ret = kernel_disable_channel(kchan);
170 if (ret < 0 && ret != -EEXIST) {
171 ret = LTTNG_ERR_KERN_CHAN_DISABLE_FAIL;
172 goto error;
173 }
174 }
175
176 ret = LTTNG_OK;
177
178 error:
179 return ret;
180 }
181
182 /*
183 * Enable kernel channel of the kernel session.
184 */
185 int channel_kernel_enable(struct ltt_kernel_session *ksession,
186 struct ltt_kernel_channel *kchan)
187 {
188 int ret;
189
190 assert(ksession);
191 assert(kchan);
192
193 if (kchan->enabled == 0) {
194 ret = kernel_enable_channel(kchan);
195 if (ret < 0) {
196 ret = LTTNG_ERR_KERN_CHAN_ENABLE_FAIL;
197 goto error;
198 }
199 } else {
200 ret = LTTNG_ERR_KERN_CHAN_EXIST;
201 goto error;
202 }
203
204 ret = LTTNG_OK;
205
206 error:
207 return ret;
208 }
209
210 static int channel_validate(struct lttng_channel *attr)
211 {
212 /*
213 * The ringbuffer (both in user space and kernel) behaves badly
214 * in overwrite mode and with less than 2 subbuffers so block it
215 * right away and send back an invalid attribute error.
216 */
217 if (attr->attr.overwrite && attr->attr.num_subbuf < 2) {
218 return -1;
219 }
220 return 0;
221 }
222
223 static int channel_validate_kernel(struct lttng_channel *attr)
224 {
225 /* Kernel channels do not support blocking timeout. */
226 if (((struct lttng_channel_extended *)attr->attr.extended.ptr)->blocking_timeout) {
227 return -1;
228 }
229 return 0;
230 }
231
232 /*
233 * Create kernel channel of the kernel session and notify kernel thread.
234 */
235 int channel_kernel_create(struct ltt_kernel_session *ksession,
236 struct lttng_channel *attr, int kernel_pipe)
237 {
238 int ret;
239 struct lttng_channel *defattr = NULL;
240
241 assert(ksession);
242
243 /* Creating channel attributes if needed */
244 if (attr == NULL) {
245 defattr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
246 LTTNG_BUFFER_GLOBAL);
247 if (defattr == NULL) {
248 ret = LTTNG_ERR_FATAL;
249 goto error;
250 }
251 attr = defattr;
252 }
253
254 /*
255 * Set the overwrite mode for this channel based on the session
256 * type unless the client explicitly overrides the channel mode.
257 */
258 if (attr->attr.overwrite == DEFAULT_CHANNEL_OVERWRITE) {
259 attr->attr.overwrite = !!ksession->snapshot_mode;
260 }
261
262 /* Enforce mmap output for snapshot sessions. */
263 if (ksession->snapshot_mode) {
264 attr->attr.output = LTTNG_EVENT_MMAP;
265 }
266
267 /* Validate common channel properties. */
268 if (channel_validate(attr) < 0) {
269 ret = LTTNG_ERR_INVALID;
270 goto error;
271 }
272
273 if (channel_validate_kernel(attr) < 0) {
274 ret = LTTNG_ERR_INVALID;
275 goto error;
276 }
277
278 /* Channel not found, creating it */
279 ret = kernel_create_channel(ksession, attr);
280 if (ret < 0) {
281 ret = LTTNG_ERR_KERN_CHAN_FAIL;
282 goto error;
283 }
284
285 /* Notify kernel thread that there is a new channel */
286 ret = notify_thread_pipe(kernel_pipe);
287 if (ret < 0) {
288 ret = LTTNG_ERR_FATAL;
289 goto error;
290 }
291
292 ret = LTTNG_OK;
293 error:
294 channel_attr_destroy(defattr);
295 return ret;
296 }
297
298 /*
299 * Enable UST channel for session and domain.
300 */
301 int channel_ust_enable(struct ltt_ust_session *usess,
302 struct ltt_ust_channel *uchan)
303 {
304 int ret = LTTNG_OK;
305
306 assert(usess);
307 assert(uchan);
308
309 /* If already enabled, everything is OK */
310 if (uchan->enabled) {
311 DBG3("Channel %s already enabled. Skipping", uchan->name);
312 ret = LTTNG_ERR_UST_CHAN_EXIST;
313 goto end;
314 }
315
316 DBG2("Channel %s being enabled in UST domain", uchan->name);
317
318 /*
319 * Enable channel for UST global domain on all applications. Ignore return
320 * value here since whatever error we got, it means that the channel was
321 * not created on one or many registered applications and we can not report
322 * this to the user yet. However, at this stage, the channel was
323 * successfully created on the session daemon side so the enable-channel
324 * command is a success.
325 */
326 (void) ust_app_enable_channel_glb(usess, uchan);
327
328 uchan->enabled = 1;
329 DBG2("Channel %s enabled successfully", uchan->name);
330
331 end:
332 return ret;
333 }
334
335 /*
336 * Create UST channel for session and domain.
337 */
338 int channel_ust_create(struct ltt_ust_session *usess,
339 struct lttng_channel *attr, enum lttng_buffer_type type)
340 {
341 int ret = LTTNG_OK;
342 struct ltt_ust_channel *uchan = NULL;
343 struct lttng_channel *defattr = NULL;
344 enum lttng_domain_type domain = LTTNG_DOMAIN_UST;
345
346 assert(usess);
347
348 /* Creating channel attributes if needed */
349 if (attr == NULL) {
350 defattr = channel_new_default_attr(LTTNG_DOMAIN_UST, type);
351 if (defattr == NULL) {
352 ret = LTTNG_ERR_FATAL;
353 goto error;
354 }
355 attr = defattr;
356 } else {
357 /*
358 * HACK: Set the channel's subdomain (JUL, Log4j, Python, etc.)
359 * based on the default name.
360 */
361 if (!strcmp(attr->name, DEFAULT_JUL_CHANNEL_NAME)) {
362 domain = LTTNG_DOMAIN_JUL;
363 } else if (!strcmp(attr->name, DEFAULT_LOG4J_CHANNEL_NAME)) {
364 domain = LTTNG_DOMAIN_LOG4J;
365 } else if (!strcmp(attr->name, DEFAULT_PYTHON_CHANNEL_NAME)) {
366 domain = LTTNG_DOMAIN_PYTHON;
367 }
368 }
369
370 /*
371 * Set the overwrite mode for this channel based on the session
372 * type unless the client explicitly overrides the channel mode.
373 */
374 if (attr->attr.overwrite == DEFAULT_CHANNEL_OVERWRITE) {
375 attr->attr.overwrite = !!usess->snapshot_mode;
376 }
377
378 /* Enforce mmap output for snapshot sessions. */
379 if (usess->snapshot_mode) {
380 attr->attr.output = LTTNG_EVENT_MMAP;
381 }
382
383 /* Validate common channel properties. */
384 if (channel_validate(attr) < 0) {
385 ret = LTTNG_ERR_INVALID;
386 goto error;
387 }
388
389 /*
390 * Validate UST buffer size and number of buffers: must both be power of 2
391 * and nonzero. We validate right here for UST, because applications will
392 * not report the error to the user (unlike kernel tracing).
393 */
394 if (!attr->attr.subbuf_size ||
395 (attr->attr.subbuf_size & (attr->attr.subbuf_size - 1))) {
396 ret = LTTNG_ERR_INVALID;
397 goto error;
398 }
399
400 /*
401 * Invalid subbuffer size if it's lower then the page size.
402 */
403 if (attr->attr.subbuf_size < page_size) {
404 ret = LTTNG_ERR_INVALID;
405 goto error;
406 }
407
408 if (!attr->attr.num_subbuf ||
409 (attr->attr.num_subbuf & (attr->attr.num_subbuf - 1))) {
410 ret = LTTNG_ERR_INVALID;
411 goto error;
412 }
413
414 if (attr->attr.output != LTTNG_EVENT_MMAP) {
415 ret = LTTNG_ERR_NOT_SUPPORTED;
416 goto error;
417 }
418
419 /*
420 * The tracefile_size should not be < to the subbuf_size, otherwise
421 * we won't be able to write the packets on disk
422 */
423 if ((attr->attr.tracefile_size > 0) &&
424 (attr->attr.tracefile_size < attr->attr.subbuf_size)) {
425 ret = LTTNG_ERR_INVALID;
426 goto error;
427 }
428
429 /* Validate buffer type. */
430 switch (type) {
431 case LTTNG_BUFFER_PER_PID:
432 break;
433 case LTTNG_BUFFER_PER_UID:
434 break;
435 default:
436 ret = LTTNG_ERR_BUFFER_NOT_SUPPORTED;
437 goto error;
438 }
439
440 /* Create UST channel */
441 uchan = trace_ust_create_channel(attr, domain);
442 if (uchan == NULL) {
443 ret = LTTNG_ERR_FATAL;
444 goto error;
445 }
446
447 uchan->enabled = 1;
448 if (trace_ust_is_max_id(usess->used_channel_id)) {
449 ret = LTTNG_ERR_UST_CHAN_FAIL;
450 goto error;
451 }
452 uchan->id = trace_ust_get_next_chan_id(usess);
453
454 DBG2("Channel %s is being created for UST with buffer %d and id %" PRIu64,
455 uchan->name, type, uchan->id);
456
457 /* Flag session buffer type. */
458 if (!usess->buffer_type_changed) {
459 usess->buffer_type = type;
460 usess->buffer_type_changed = 1;
461 } else if (usess->buffer_type != type) {
462 /* Buffer type was already set. Refuse to create channel. */
463 ret = LTTNG_ERR_BUFFER_TYPE_MISMATCH;
464 goto error_free_chan;
465 }
466
467 /* Enable channel for global domain */
468 ret = ust_app_create_channel_glb(usess, uchan);
469 if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
470 ret = LTTNG_ERR_UST_CHAN_FAIL;
471 goto error_free_chan;
472 }
473
474 /* Adding the channel to the channel hash table. */
475 rcu_read_lock();
476 if (strncmp(uchan->name, DEFAULT_METADATA_NAME,
477 sizeof(uchan->name))) {
478 lttng_ht_add_unique_str(usess->domain_global.channels, &uchan->node);
479 } else {
480 /*
481 * Copy channel attribute to session if this is metadata so if NO
482 * application exists we can access that data in the shadow copy during
483 * the global update of newly registered application.
484 */
485 memcpy(&usess->metadata_attr, &uchan->attr,
486 sizeof(usess->metadata_attr));
487 }
488 rcu_read_unlock();
489
490 DBG2("Channel %s created successfully", uchan->name);
491 if (domain != LTTNG_DOMAIN_UST) {
492 struct agent *agt = trace_ust_find_agent(usess, domain);
493
494 if (!agt) {
495 agt = agent_create(domain);
496 if (!agt) {
497 ret = LTTNG_ERR_NOMEM;
498 goto error_free_chan;
499 }
500 agent_add(agt, usess->agents);
501 }
502 }
503
504 channel_attr_destroy(defattr);
505 return LTTNG_OK;
506
507 error_free_chan:
508 /*
509 * No need to remove the channel from the hash table because at this point
510 * it was not added hence the direct call and no call_rcu().
511 */
512 trace_ust_destroy_channel(uchan);
513 error:
514 channel_attr_destroy(defattr);
515 return ret;
516 }
517
518 /*
519 * Disable UST channel for session and domain.
520 */
521 int channel_ust_disable(struct ltt_ust_session *usess,
522 struct ltt_ust_channel *uchan)
523 {
524 int ret = LTTNG_OK;
525
526 assert(usess);
527 assert(uchan);
528
529 /* Already disabled */
530 if (uchan->enabled == 0) {
531 DBG2("Channel UST %s already disabled", uchan->name);
532 goto end;
533 }
534
535 DBG2("Channel %s being disabled in UST global domain", uchan->name);
536 /* Disable channel for global domain */
537 ret = ust_app_disable_channel_glb(usess, uchan);
538 if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
539 ret = LTTNG_ERR_UST_CHAN_DISABLE_FAIL;
540 goto error;
541 }
542
543 uchan->enabled = 0;
544
545 DBG2("Channel %s disabled successfully", uchan->name);
546
547 return LTTNG_OK;
548
549 end:
550 error:
551 return ret;
552 }
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