Create agent on channel creation
[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
45 chan = zmalloc(sizeof(struct lttng_channel));
46 if (chan == NULL) {
47 PERROR("zmalloc channel init");
48 goto error_alloc;
49 }
50
51 /* Same for all domains. */
52 chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
53 chan->attr.tracefile_size = DEFAULT_CHANNEL_TRACEFILE_SIZE;
54 chan->attr.tracefile_count = DEFAULT_CHANNEL_TRACEFILE_COUNT;
55
56 switch (dom) {
57 case LTTNG_DOMAIN_KERNEL:
58 assert(type == LTTNG_BUFFER_GLOBAL);
59 chan->attr.subbuf_size =
60 default_get_kernel_channel_subbuf_size();
61 chan->attr.num_subbuf = DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM;
62 chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
63 chan->attr.switch_timer_interval = DEFAULT_KERNEL_CHANNEL_SWITCH_TIMER;
64 chan->attr.read_timer_interval = DEFAULT_KERNEL_CHANNEL_READ_TIMER;
65 chan->attr.live_timer_interval = DEFAULT_KERNEL_CHANNEL_LIVE_TIMER;
66 break;
67 case LTTNG_DOMAIN_JUL:
68 channel_name = DEFAULT_JUL_CHANNEL_NAME;
69 goto common_ust;
70 case LTTNG_DOMAIN_LOG4J:
71 channel_name = DEFAULT_LOG4J_CHANNEL_NAME;
72 goto common_ust;
73 case LTTNG_DOMAIN_PYTHON:
74 channel_name = DEFAULT_PYTHON_CHANNEL_NAME;
75 goto common_ust;
76 case LTTNG_DOMAIN_UST:
77 common_ust:
78 switch (type) {
79 case LTTNG_BUFFER_PER_UID:
80 chan->attr.subbuf_size = default_get_ust_uid_channel_subbuf_size();
81 chan->attr.num_subbuf = DEFAULT_UST_UID_CHANNEL_SUBBUF_NUM;
82 chan->attr.output = DEFAULT_UST_UID_CHANNEL_OUTPUT;
83 chan->attr.switch_timer_interval =
84 DEFAULT_UST_UID_CHANNEL_SWITCH_TIMER;
85 chan->attr.read_timer_interval =
86 DEFAULT_UST_UID_CHANNEL_READ_TIMER;
87 chan->attr.live_timer_interval =
88 DEFAULT_UST_UID_CHANNEL_LIVE_TIMER;
89 break;
90 case LTTNG_BUFFER_PER_PID:
91 default:
92 chan->attr.subbuf_size = default_get_ust_pid_channel_subbuf_size();
93 chan->attr.num_subbuf = DEFAULT_UST_PID_CHANNEL_SUBBUF_NUM;
94 chan->attr.output = DEFAULT_UST_PID_CHANNEL_OUTPUT;
95 chan->attr.switch_timer_interval =
96 DEFAULT_UST_PID_CHANNEL_SWITCH_TIMER;
97 chan->attr.read_timer_interval =
98 DEFAULT_UST_PID_CHANNEL_READ_TIMER;
99 chan->attr.live_timer_interval =
100 DEFAULT_UST_UID_CHANNEL_LIVE_TIMER;
101 break;
102 }
103 break;
104 default:
105 goto error; /* Not implemented */
106 }
107
108 if (snprintf(chan->name, sizeof(chan->name), "%s",
109 channel_name) < 0) {
110 PERROR("snprintf default channel name");
111 goto error;
112 }
113 return chan;
114
115 error:
116 free(chan);
117 error_alloc:
118 return NULL;
119 }
120
121 /*
122 * Disable kernel channel of the kernel session.
123 */
124 int channel_kernel_disable(struct ltt_kernel_session *ksession,
125 char *channel_name)
126 {
127 int ret;
128 struct ltt_kernel_channel *kchan;
129
130 assert(ksession);
131 assert(channel_name);
132
133 kchan = trace_kernel_get_channel_by_name(channel_name, ksession);
134 if (kchan == NULL) {
135 ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND;
136 goto error;
137 }
138
139 /* Only if channel is enabled disable it. */
140 if (kchan->enabled == 1) {
141 ret = kernel_disable_channel(kchan);
142 if (ret < 0 && ret != -EEXIST) {
143 ret = LTTNG_ERR_KERN_CHAN_DISABLE_FAIL;
144 goto error;
145 }
146 }
147
148 ret = LTTNG_OK;
149
150 error:
151 return ret;
152 }
153
154 /*
155 * Enable kernel channel of the kernel session.
156 */
157 int channel_kernel_enable(struct ltt_kernel_session *ksession,
158 struct ltt_kernel_channel *kchan)
159 {
160 int ret;
161
162 assert(ksession);
163 assert(kchan);
164
165 if (kchan->enabled == 0) {
166 ret = kernel_enable_channel(kchan);
167 if (ret < 0) {
168 ret = LTTNG_ERR_KERN_CHAN_ENABLE_FAIL;
169 goto error;
170 }
171 } else {
172 ret = LTTNG_ERR_KERN_CHAN_EXIST;
173 goto error;
174 }
175
176 ret = LTTNG_OK;
177
178 error:
179 return ret;
180 }
181
182 /*
183 * Create kernel channel of the kernel session and notify kernel thread.
184 */
185 int channel_kernel_create(struct ltt_kernel_session *ksession,
186 struct lttng_channel *attr, int kernel_pipe)
187 {
188 int ret;
189 struct lttng_channel *defattr = NULL;
190
191 assert(ksession);
192
193 /* Creating channel attributes if needed */
194 if (attr == NULL) {
195 defattr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL,
196 LTTNG_BUFFER_GLOBAL);
197 if (defattr == NULL) {
198 ret = LTTNG_ERR_FATAL;
199 goto error;
200 }
201 attr = defattr;
202 }
203
204 if (ksession->snapshot_mode) {
205 /* Force channel attribute for snapshot mode. */
206 attr->attr.overwrite = 1;
207 attr->attr.output = LTTNG_EVENT_MMAP;
208 }
209
210 /* Channel not found, creating it */
211 ret = kernel_create_channel(ksession, attr);
212 if (ret < 0) {
213 ret = LTTNG_ERR_KERN_CHAN_FAIL;
214 goto error;
215 }
216
217 /* Notify kernel thread that there is a new channel */
218 ret = notify_thread_pipe(kernel_pipe);
219 if (ret < 0) {
220 ret = LTTNG_ERR_FATAL;
221 goto error;
222 }
223
224 ret = LTTNG_OK;
225 error:
226 free(defattr);
227 return ret;
228 }
229
230 /*
231 * Enable UST channel for session and domain.
232 */
233 int channel_ust_enable(struct ltt_ust_session *usess,
234 struct ltt_ust_channel *uchan)
235 {
236 int ret = LTTNG_OK;
237
238 assert(usess);
239 assert(uchan);
240
241 /* If already enabled, everything is OK */
242 if (uchan->enabled) {
243 DBG3("Channel %s already enabled. Skipping", uchan->name);
244 ret = LTTNG_ERR_UST_CHAN_EXIST;
245 goto end;
246 }
247
248 DBG2("Channel %s being enabled in UST domain", uchan->name);
249
250 /*
251 * Enable channel for UST global domain on all applications. Ignore return
252 * value here since whatever error we got, it means that the channel was
253 * not created on one or many registered applications and we can not report
254 * this to the user yet. However, at this stage, the channel was
255 * successfully created on the session daemon side so the enable-channel
256 * command is a success.
257 */
258 (void) ust_app_enable_channel_glb(usess, uchan);
259
260 uchan->enabled = 1;
261 DBG2("Channel %s enabled successfully", uchan->name);
262
263 end:
264 return ret;
265 }
266
267 /*
268 * Create UST channel for session and domain.
269 */
270 int channel_ust_create(struct ltt_ust_session *usess,
271 struct lttng_channel *attr, enum lttng_buffer_type type)
272 {
273 int ret = LTTNG_OK;
274 struct ltt_ust_channel *uchan = NULL;
275 struct lttng_channel *defattr = NULL;
276 enum lttng_domain_type domain = LTTNG_DOMAIN_UST;
277
278 assert(usess);
279
280 /* Creating channel attributes if needed */
281 if (attr == NULL) {
282 defattr = channel_new_default_attr(LTTNG_DOMAIN_UST, type);
283 if (defattr == NULL) {
284 ret = LTTNG_ERR_FATAL;
285 goto error;
286 }
287 attr = defattr;
288 } else {
289 /*
290 * HACK: Set the channel's subdomain (JUL, Log4j, Python, etc.)
291 * based on the default name.
292 */
293 if (!strcmp(attr->name, DEFAULT_JUL_CHANNEL_NAME)) {
294 domain = LTTNG_DOMAIN_JUL;
295 } else if (!strcmp(attr->name, DEFAULT_LOG4J_CHANNEL_NAME)) {
296 domain = LTTNG_DOMAIN_LOG4J;
297 } else if (!strcmp(attr->name, DEFAULT_PYTHON_CHANNEL_NAME)) {
298 domain = LTTNG_DOMAIN_PYTHON;
299 }
300 }
301
302 if (usess->snapshot_mode) {
303 /* Force channel attribute for snapshot mode. */
304 attr->attr.overwrite = 1;
305 attr->attr.output = LTTNG_EVENT_MMAP;
306 }
307
308 /*
309 * Validate UST buffer size and number of buffers: must both be power of 2
310 * and nonzero. We validate right here for UST, because applications will
311 * not report the error to the user (unlike kernel tracing).
312 */
313 if (!attr->attr.subbuf_size ||
314 (attr->attr.subbuf_size & (attr->attr.subbuf_size - 1))) {
315 ret = LTTNG_ERR_INVALID;
316 goto error;
317 }
318
319 /*
320 * Invalid subbuffer size if it's lower then the page size.
321 */
322 if (attr->attr.subbuf_size < page_size) {
323 ret = LTTNG_ERR_INVALID;
324 goto error;
325 }
326
327 if (!attr->attr.num_subbuf ||
328 (attr->attr.num_subbuf & (attr->attr.num_subbuf - 1))) {
329 ret = LTTNG_ERR_INVALID;
330 goto error;
331 }
332
333 if (attr->attr.output != LTTNG_EVENT_MMAP) {
334 ret = LTTNG_ERR_NOT_SUPPORTED;
335 goto error;
336 }
337
338 /*
339 * The tracefile_size should not be < to the subbuf_size, otherwise
340 * we won't be able to write the packets on disk
341 */
342 if ((attr->attr.tracefile_size > 0) &&
343 (attr->attr.tracefile_size < attr->attr.subbuf_size)) {
344 ret = LTTNG_ERR_INVALID;
345 goto error;
346 }
347
348 /* Validate buffer type. */
349 switch (type) {
350 case LTTNG_BUFFER_PER_PID:
351 break;
352 case LTTNG_BUFFER_PER_UID:
353 break;
354 default:
355 ret = LTTNG_ERR_BUFFER_NOT_SUPPORTED;
356 goto error;
357 }
358
359 /* Create UST channel */
360 uchan = trace_ust_create_channel(attr, domain);
361 if (uchan == NULL) {
362 ret = LTTNG_ERR_FATAL;
363 goto error;
364 }
365
366 uchan->enabled = 1;
367 if (trace_ust_is_max_id(usess->used_channel_id)) {
368 ret = LTTNG_ERR_UST_CHAN_FAIL;
369 goto error;
370 }
371 uchan->id = trace_ust_get_next_chan_id(usess);
372
373 DBG2("Channel %s is being created for UST with buffer %d and id %" PRIu64,
374 uchan->name, type, uchan->id);
375
376 /* Flag session buffer type. */
377 if (!usess->buffer_type_changed) {
378 usess->buffer_type = type;
379 usess->buffer_type_changed = 1;
380 } else if (usess->buffer_type != type) {
381 /* Buffer type was already set. Refuse to create channel. */
382 ret = LTTNG_ERR_BUFFER_TYPE_MISMATCH;
383 goto error_free_chan;
384 }
385
386 /* Enable channel for global domain */
387 ret = ust_app_create_channel_glb(usess, uchan);
388 if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
389 ret = LTTNG_ERR_UST_CHAN_FAIL;
390 goto error_free_chan;
391 }
392
393 /* Adding the channel to the channel hash table. */
394 rcu_read_lock();
395 if (strncmp(uchan->name, DEFAULT_METADATA_NAME,
396 sizeof(uchan->name))) {
397 lttng_ht_add_unique_str(usess->domain_global.channels, &uchan->node);
398 } else {
399 /*
400 * Copy channel attribute to session if this is metadata so if NO
401 * application exists we can access that data in the shadow copy during
402 * the global update of newly registered application.
403 */
404 memcpy(&usess->metadata_attr, &uchan->attr,
405 sizeof(usess->metadata_attr));
406 }
407 rcu_read_unlock();
408
409 DBG2("Channel %s created successfully", uchan->name);
410 if (domain != LTTNG_DOMAIN_UST) {
411 struct agent *agt = trace_ust_find_agent(usess, domain);
412
413 if (!agt) {
414 agt = agent_create(domain);
415 if (!agt) {
416 ret = LTTNG_ERR_NOMEM;
417 goto error_free_chan;
418 }
419 agent_add(agt, usess->agents);
420 }
421 }
422
423 free(defattr);
424 return LTTNG_OK;
425
426 error_free_chan:
427 /*
428 * No need to remove the channel from the hash table because at this point
429 * it was not added hence the direct call and no call_rcu().
430 */
431 trace_ust_destroy_channel(uchan);
432 error:
433 free(defattr);
434 return ret;
435 }
436
437 /*
438 * Disable UST channel for session and domain.
439 */
440 int channel_ust_disable(struct ltt_ust_session *usess,
441 struct ltt_ust_channel *uchan)
442 {
443 int ret = LTTNG_OK;
444
445 assert(usess);
446 assert(uchan);
447
448 /* Already disabled */
449 if (uchan->enabled == 0) {
450 DBG2("Channel UST %s already disabled", uchan->name);
451 goto end;
452 }
453
454 DBG2("Channel %s being disabled in UST global domain", uchan->name);
455 /* Disable channel for global domain */
456 ret = ust_app_disable_channel_glb(usess, uchan);
457 if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) {
458 ret = LTTNG_ERR_UST_CHAN_DISABLE_FAIL;
459 goto error;
460 }
461
462 uchan->enabled = 0;
463
464 DBG2("Channel %s disabled successfully", uchan->name);
465
466 return LTTNG_OK;
467
468 end:
469 error:
470 return ret;
471 }
This page took 0.060668 seconds and 4 git commands to generate.