Refactor JUL to agent namespace
[lttng-tools.git] / src / bin / lttng-sessiond / agent.c
CommitLineData
0475c50c
DG
1/*
2 * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License, version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 51
15 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18#define _GNU_SOURCE
19#include <assert.h>
f20baf8e 20#include <urcu/uatomic.h>
0475c50c
DG
21
22#include <common/common.h>
022d91ba 23#include <common/sessiond-comm/agent.h>
0475c50c 24
f263b7fd
JD
25#include <common/compat/endian.h>
26
022d91ba 27#include "agent.h"
f20baf8e 28#include "ust-app.h"
0475c50c
DG
29#include "utils.h"
30
4a4ab2c3
DG
31/*
32 * Match function for the events hash table lookup by name.
33 */
34static int ht_match_event_by_name(struct cds_lfht_node *node,
35 const void *_key)
36{
022d91ba
DG
37 struct agent_event *event;
38 const struct agent_ht_key *key;
4a4ab2c3
DG
39
40 assert(node);
41 assert(_key);
42
022d91ba 43 event = caa_container_of(node, struct agent_event, node.node);
4a4ab2c3
DG
44 key = _key;
45
46 /* Match 1 elements of the key: name. */
47
48 /* Event name */
49 if (strncmp(event->name, key->name, sizeof(event->name)) != 0) {
50 goto no_match;
51 }
52 /* Match. */
53 return 1;
54
55no_match:
56 return 0;
57}
58
59/*
60 * Match function for the events hash table lookup by name and loglevel.
61 */
62static int ht_match_event(struct cds_lfht_node *node,
63 const void *_key)
64{
022d91ba
DG
65 struct agent_event *event;
66 const struct agent_ht_key *key;
4a4ab2c3
DG
67
68 assert(node);
69 assert(_key);
70
022d91ba 71 event = caa_container_of(node, struct agent_event, node.node);
4a4ab2c3
DG
72 key = _key;
73
74 /* Match 2 elements of the key: name and loglevel. */
75
76 /* Event name */
77 if (strncmp(event->name, key->name, sizeof(event->name)) != 0) {
78 goto no_match;
79 }
80
81 if (event->loglevel != key->loglevel) {
82 if (event->loglevel_type == LTTNG_EVENT_LOGLEVEL_ALL &&
83 key->loglevel == 0 && event->loglevel == -1) {
84 goto match;
85 }
86 goto no_match;
87 }
88match:
89 return 1;
90
91no_match:
92 return 0;
93}
94
95/*
022d91ba 96 * Add unique agent event based on the event name and loglevel.
4a4ab2c3 97 */
022d91ba
DG
98static void add_unique_agent_event(struct lttng_ht *ht,
99 struct agent_event *event)
4a4ab2c3
DG
100{
101 struct cds_lfht_node *node_ptr;
022d91ba 102 struct agent_ht_key key;
4a4ab2c3
DG
103
104 assert(ht);
105 assert(ht->ht);
106 assert(event);
107
108 key.name = event->name;
109 key.loglevel = event->loglevel;
110
111 node_ptr = cds_lfht_add_unique(ht->ht,
112 ht->hash_fct(event->node.key, lttng_ht_seed),
113 ht_match_event, &key, &event->node.node);
114 assert(node_ptr == &event->node.node);
115}
116
0475c50c 117/*
022d91ba 118 * URCU delayed agent event reclaim.
0475c50c 119 */
022d91ba 120static void destroy_event_agent_rcu(struct rcu_head *head)
0475c50c
DG
121{
122 struct lttng_ht_node_str *node =
123 caa_container_of(head, struct lttng_ht_node_str, head);
022d91ba
DG
124 struct agent_event *event =
125 caa_container_of(node, struct agent_event, node);
0475c50c
DG
126
127 free(event);
128}
129
f20baf8e 130/*
022d91ba 131 * URCU delayed agent app reclaim.
f20baf8e 132 */
022d91ba 133static void destroy_app_agent_rcu(struct rcu_head *head)
f20baf8e
DG
134{
135 struct lttng_ht_node_ulong *node =
136 caa_container_of(head, struct lttng_ht_node_ulong, head);
022d91ba
DG
137 struct agent_app *app =
138 caa_container_of(node, struct agent_app, node);
f20baf8e
DG
139
140 free(app);
141}
142
143/*
022d91ba
DG
144 * Communication with the agent. Send the message header to the given socket in
145 * big endian.
f20baf8e
DG
146 *
147 * Return 0 on success or else a negative errno message of sendmsg() op.
148 */
149static int send_header(struct lttcomm_sock *sock, uint64_t data_size,
150 uint32_t cmd, uint32_t cmd_version)
151{
152 int ret;
153 ssize_t size;
022d91ba 154 struct lttcomm_agent_hdr msg;
f20baf8e
DG
155
156 assert(sock);
157
53efb85a 158 memset(&msg, 0, sizeof(msg));
f20baf8e
DG
159 msg.data_size = htobe64(data_size);
160 msg.cmd = htobe32(cmd);
161 msg.cmd_version = htobe32(cmd_version);
162
163 size = sock->ops->sendmsg(sock, &msg, sizeof(msg), 0);
164 if (size < sizeof(msg)) {
165 ret = -errno;
166 goto error;
167 }
168 ret = 0;
169
170error:
171 return ret;
172}
173
174/*
022d91ba
DG
175 * Communication call with the agent. Send the payload to the given socket. The
176 * header MUST be sent prior to this call.
f20baf8e
DG
177 *
178 * Return 0 on success or else a negative errno value of sendmsg() op.
179 */
180static int send_payload(struct lttcomm_sock *sock, void *data,
181 size_t size)
182{
183 int ret;
184 ssize_t len;
185
186 assert(sock);
187 assert(data);
188
189 len = sock->ops->sendmsg(sock, data, size, 0);
190 if (len < size) {
191 ret = -errno;
192 goto error;
193 }
194 ret = 0;
195
196error:
197 return ret;
198}
199
200/*
022d91ba
DG
201 * Communication call with the agent. Receive reply from the agent using the
202 * given socket.
f20baf8e
DG
203 *
204 * Return 0 on success or else a negative errno value from recvmsg() op.
205 */
206static int recv_reply(struct lttcomm_sock *sock, void *buf, size_t size)
207{
208 int ret;
209 ssize_t len;
210
211 assert(sock);
212 assert(buf);
213
214 len = sock->ops->recvmsg(sock, buf, size, 0);
215 if (len < size) {
216 ret = -errno;
217 goto error;
218 }
219 ret = 0;
220
221error:
222 return ret;
223}
224
3c6a091f 225/*
428de77a 226 * Internal event listing for a given app. Populate events.
3c6a091f
DG
227 *
228 * Return number of element in the list or else a negative LTTNG_ERR* code.
428de77a
MD
229 * On success, the caller is responsible for freeing the memory
230 * allocated for "events".
3c6a091f 231 */
022d91ba 232static ssize_t list_events(struct agent_app *app, struct lttng_event **events)
3c6a091f
DG
233{
234 int ret, i, len = 0, offset = 0;
235 uint32_t nb_event;
236 size_t data_size;
237 struct lttng_event *tmp_events = NULL;
022d91ba
DG
238 struct lttcomm_agent_list_reply *reply = NULL;
239 struct lttcomm_agent_list_reply_hdr reply_hdr;
3c6a091f
DG
240
241 assert(app);
242 assert(app->sock);
243 assert(events);
244
022d91ba 245 DBG2("Agent listing events for app pid: %d and socket %d", app->pid,
3c6a091f
DG
246 app->sock->fd);
247
022d91ba 248 ret = send_header(app->sock, 0, AGENT_CMD_LIST, 0);
3c6a091f
DG
249 if (ret < 0) {
250 goto error_io;
251 }
252
253 /* Get list header so we know how much we'll receive. */
254 ret = recv_reply(app->sock, &reply_hdr, sizeof(reply_hdr));
255 if (ret < 0) {
256 goto error_io;
257 }
258
259 switch (be32toh(reply_hdr.ret_code)) {
022d91ba 260 case AGENT_RET_CODE_SUCCESS:
3c6a091f
DG
261 data_size = be32toh(reply_hdr.data_size) + sizeof(*reply);
262 break;
263 default:
022d91ba 264 ERR("Agent returned an unknown code: %" PRIu32,
3c6a091f
DG
265 be32toh(reply_hdr.ret_code));
266 ret = LTTNG_ERR_FATAL;
267 goto error;
268 }
269
270 reply = zmalloc(data_size);
271 if (!reply) {
272 ret = LTTNG_ERR_NOMEM;
273 goto error;
274 }
275
276 /* Get the list with the appropriate data size. */
277 ret = recv_reply(app->sock, reply, data_size);
278 if (ret < 0) {
279 goto error_io;
280 }
281
282 nb_event = be32toh(reply->nb_event);
283 tmp_events = zmalloc(sizeof(*tmp_events) * nb_event);
284 if (!tmp_events) {
285 ret = LTTNG_ERR_NOMEM;
286 goto error;
287 }
288
289 for (i = 0; i < nb_event; i++) {
290 offset += len;
291 strncpy(tmp_events[i].name, reply->payload + offset,
292 sizeof(tmp_events[i].name));
293 tmp_events[i].pid = app->pid;
294 tmp_events[i].enabled = -1;
295 len = strlen(reply->payload + offset) + 1;
296 }
297
298 *events = tmp_events;
299
300 free(reply);
301 return nb_event;
302
303error_io:
304 ret = LTTNG_ERR_UST_LIST_FAIL;
305error:
306 free(reply);
307 free(tmp_events);
308 return -ret;
309
310}
311
f20baf8e 312/*
022d91ba
DG
313 * Internal enable agent event on a agent application. This function
314 * communicates with the agent to enable a given event.
f20baf8e
DG
315 *
316 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
317 */
022d91ba 318static int enable_event(struct agent_app *app, struct agent_event *event)
f20baf8e
DG
319{
320 int ret;
321 uint64_t data_size;
022d91ba
DG
322 struct lttcomm_agent_enable msg;
323 struct lttcomm_agent_generic_reply reply;
f20baf8e
DG
324
325 assert(app);
326 assert(app->sock);
327 assert(event);
328
022d91ba 329 DBG2("Agent enabling event %s for app pid: %d and socket %d", event->name,
f20baf8e
DG
330 app->pid, app->sock->fd);
331
332 data_size = sizeof(msg);
333
022d91ba 334 ret = send_header(app->sock, data_size, AGENT_CMD_ENABLE, 0);
f20baf8e
DG
335 if (ret < 0) {
336 goto error_io;
337 }
338
53efb85a 339 memset(&msg, 0, sizeof(msg));
b2064f54
DG
340 msg.loglevel = event->loglevel;
341 msg.loglevel_type = event->loglevel_type;
f20baf8e
DG
342 strncpy(msg.name, event->name, sizeof(msg.name));
343 ret = send_payload(app->sock, &msg, sizeof(msg));
344 if (ret < 0) {
345 goto error_io;
346 }
347
348 ret = recv_reply(app->sock, &reply, sizeof(reply));
349 if (ret < 0) {
350 goto error_io;
351 }
352
353 switch (be32toh(reply.ret_code)) {
022d91ba 354 case AGENT_RET_CODE_SUCCESS:
f20baf8e 355 break;
022d91ba 356 case AGENT_RET_CODE_UNKNOWN_NAME:
f20baf8e
DG
357 ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
358 goto error;
359 default:
022d91ba 360 ERR("Agent returned an unknown code: %" PRIu32,
f20baf8e
DG
361 be32toh(reply.ret_code));
362 ret = LTTNG_ERR_FATAL;
363 goto error;
364 }
365
366 return LTTNG_OK;
367
368error_io:
369 ret = LTTNG_ERR_UST_ENABLE_FAIL;
370error:
371 return ret;
372}
373
374/*
022d91ba
DG
375 * Internal disable agent event call on a agent application. This function
376 * communicates with the agent to disable a given event.
f20baf8e
DG
377 *
378 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
379 */
022d91ba 380static int disable_event(struct agent_app *app, struct agent_event *event)
f20baf8e
DG
381{
382 int ret;
383 uint64_t data_size;
022d91ba
DG
384 struct lttcomm_agent_disable msg;
385 struct lttcomm_agent_generic_reply reply;
f20baf8e
DG
386
387 assert(app);
388 assert(app->sock);
389 assert(event);
390
022d91ba 391 DBG2("Agent disabling event %s for app pid: %d and socket %d", event->name,
f20baf8e
DG
392 app->pid, app->sock->fd);
393
394 data_size = sizeof(msg);
395
022d91ba 396 ret = send_header(app->sock, data_size, AGENT_CMD_DISABLE, 0);
f20baf8e
DG
397 if (ret < 0) {
398 goto error_io;
399 }
400
53efb85a 401 memset(&msg, 0, sizeof(msg));
f20baf8e
DG
402 strncpy(msg.name, event->name, sizeof(msg.name));
403 ret = send_payload(app->sock, &msg, sizeof(msg));
404 if (ret < 0) {
405 goto error_io;
406 }
407
408 ret = recv_reply(app->sock, &reply, sizeof(reply));
409 if (ret < 0) {
410 goto error_io;
411 }
412
413 switch (be32toh(reply.ret_code)) {
022d91ba
DG
414 case AGENT_RET_CODE_SUCCESS:
415 break;
416 case AGENT_RET_CODE_UNKNOWN_NAME:
417 ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
418 goto error;
419 default:
420 ERR("Agent returned an unknown code: %" PRIu32,
421 be32toh(reply.ret_code));
422 ret = LTTNG_ERR_FATAL;
423 goto error;
f20baf8e
DG
424 }
425
426 return LTTNG_OK;
427
428error_io:
429 ret = LTTNG_ERR_UST_DISABLE_FAIL;
430error:
431 return ret;
432}
433
1b500e7a 434/*
022d91ba 435 * Send back the registration DONE command to a given agent application.
1b500e7a
DG
436 *
437 * Return 0 on success or else a negative value.
438 */
022d91ba 439int agent_send_registration_done(struct agent_app *app)
1b500e7a
DG
440{
441 assert(app);
442 assert(app->sock);
443
022d91ba 444 DBG("Agent sending registration done to app socket %d", app->sock->fd);
1b500e7a 445
022d91ba 446 return send_header(app->sock, 0, AGENT_CMD_REG_DONE, 0);
1b500e7a
DG
447}
448
f20baf8e 449/*
022d91ba 450 * Enable agent event on every agent applications registered with the session
f20baf8e
DG
451 * daemon.
452 *
453 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
454 */
022d91ba 455int agent_enable_event(struct agent_event *event)
f20baf8e
DG
456{
457 int ret;
022d91ba 458 struct agent_app *app;
f20baf8e
DG
459 struct lttng_ht_iter iter;
460
461 assert(event);
462
463 rcu_read_lock();
464
022d91ba 465 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
f20baf8e 466 node.node) {
022d91ba 467 /* Enable event on agent application through TCP socket. */
f20baf8e
DG
468 ret = enable_event(app, event);
469 if (ret != LTTNG_OK) {
470 goto error;
471 }
f20baf8e
DG
472 }
473
3c6a091f 474 event->enabled = 1;
f20baf8e
DG
475 ret = LTTNG_OK;
476
477error:
478 rcu_read_unlock();
479 return ret;
480}
481
482/*
022d91ba 483 * Disable agent event on every agent applications registered with the session
f20baf8e
DG
484 * daemon.
485 *
486 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
487 */
022d91ba 488int agent_disable_event(struct agent_event *event)
f20baf8e
DG
489{
490 int ret;
022d91ba 491 struct agent_app *app;
f20baf8e
DG
492 struct lttng_ht_iter iter;
493
494 assert(event);
495
496 rcu_read_lock();
497
022d91ba 498 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
f20baf8e 499 node.node) {
022d91ba 500 /* Enable event on agent application through TCP socket. */
f20baf8e
DG
501 ret = disable_event(app, event);
502 if (ret != LTTNG_OK) {
503 goto error;
504 }
f20baf8e
DG
505 }
506
3c6a091f 507 event->enabled = 0;
f20baf8e
DG
508 ret = LTTNG_OK;
509
510error:
511 rcu_read_unlock();
512 return ret;
513}
514
515/*
022d91ba
DG
516 * Ask every agent for the list of possible event. Events is allocated with the
517 * events of every agent application.
f20baf8e
DG
518 *
519 * Return the number of events or else a negative value.
520 */
022d91ba 521int agent_list_events(struct lttng_event **events)
f20baf8e
DG
522{
523 int ret;
524 size_t nbmem, count = 0;
022d91ba 525 struct agent_app *app;
aae6255e 526 struct lttng_event *tmp_events = NULL;
f20baf8e
DG
527 struct lttng_ht_iter iter;
528
529 assert(events);
530
531 nbmem = UST_APP_EVENT_LIST_SIZE;
532 tmp_events = zmalloc(nbmem * sizeof(*tmp_events));
533 if (!tmp_events) {
022d91ba 534 PERROR("zmalloc agent list events");
f20baf8e
DG
535 ret = -ENOMEM;
536 goto error;
537 }
538
539 rcu_read_lock();
022d91ba 540 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
f20baf8e
DG
541 node.node) {
542 ssize_t nb_ev;
022d91ba 543 struct lttng_event *agent_events;
f20baf8e 544
022d91ba 545 nb_ev = list_events(app, &agent_events);
f20baf8e
DG
546 if (nb_ev < 0) {
547 ret = nb_ev;
428de77a 548 goto error_unlock;
f20baf8e
DG
549 }
550
53efb85a 551 if (count + nb_ev > nbmem) {
f20baf8e 552 /* In case the realloc fails, we free the memory */
53efb85a
MD
553 struct lttng_event *new_tmp_events;
554 size_t new_nbmem;
555
556 new_nbmem = max_t(size_t, count + nb_ev, nbmem << 1);
022d91ba 557 DBG2("Reallocating agent event list from %zu to %zu entries",
53efb85a
MD
558 nbmem, new_nbmem);
559 new_tmp_events = realloc(tmp_events,
560 new_nbmem * sizeof(*new_tmp_events));
561 if (!new_tmp_events) {
022d91ba 562 PERROR("realloc agent events");
f20baf8e 563 ret = -ENOMEM;
022d91ba 564 free(agent_events);
428de77a 565 goto error_unlock;
f20baf8e 566 }
53efb85a
MD
567 /* Zero the new memory */
568 memset(new_tmp_events + nbmem, 0,
569 (new_nbmem - nbmem) * sizeof(*new_tmp_events));
570 nbmem = new_nbmem;
571 tmp_events = new_tmp_events;
f20baf8e 572 }
022d91ba 573 memcpy(tmp_events + count, agent_events,
53efb85a 574 nb_ev * sizeof(*tmp_events));
022d91ba 575 free(agent_events);
f20baf8e
DG
576 count += nb_ev;
577 }
578 rcu_read_unlock();
579
580 ret = count;
581 *events = tmp_events;
aae6255e 582 return ret;
f20baf8e 583
428de77a
MD
584error_unlock:
585 rcu_read_unlock();
f20baf8e 586error:
aae6255e 587 free(tmp_events);
f20baf8e
DG
588 return ret;
589}
590
591/*
022d91ba 592 * Create a agent app object using the given PID.
f20baf8e
DG
593 *
594 * Return newly allocated object or else NULL on error.
595 */
022d91ba 596struct agent_app *agent_create_app(pid_t pid, struct lttcomm_sock *sock)
f20baf8e 597{
022d91ba 598 struct agent_app *app;
f20baf8e
DG
599
600 assert(sock);
601
602 app = zmalloc(sizeof(*app));
603 if (!app) {
022d91ba 604 PERROR("zmalloc agent create");
f20baf8e
DG
605 goto error;
606 }
607
608 app->pid = pid;
609 app->sock = sock;
f20baf8e
DG
610 lttng_ht_node_init_ulong(&app->node, (unsigned long) app->sock->fd);
611
612error:
613 return app;
614}
615
616/*
022d91ba 617 * Lookup agent app by socket in the global hash table.
f20baf8e
DG
618 *
619 * RCU read side lock MUST be acquired.
620 *
621 * Return object if found else NULL.
622 */
022d91ba 623struct agent_app *agent_find_app_by_sock(int sock)
f20baf8e
DG
624{
625 struct lttng_ht_node_ulong *node;
626 struct lttng_ht_iter iter;
022d91ba 627 struct agent_app *app;
f20baf8e
DG
628
629 assert(sock >= 0);
630
022d91ba 631 lttng_ht_lookup(agent_apps_ht_by_sock, (void *)((unsigned long) sock), &iter);
f20baf8e
DG
632 node = lttng_ht_iter_get_node_ulong(&iter);
633 if (node == NULL) {
634 goto error;
635 }
022d91ba 636 app = caa_container_of(node, struct agent_app, node);
f20baf8e 637
022d91ba 638 DBG3("Agent app pid %d found by sock %d.", app->pid, sock);
f20baf8e
DG
639 return app;
640
641error:
022d91ba 642 DBG3("Agent app NOT found by sock %d.", sock);
f20baf8e
DG
643 return NULL;
644}
645
646/*
022d91ba 647 * Add agent application object to the global hash table.
f20baf8e 648 */
022d91ba 649void agent_add_app(struct agent_app *app)
f20baf8e
DG
650{
651 assert(app);
652
022d91ba 653 DBG3("Agent adding app sock: %d and pid: %d to ht", app->sock->fd, app->pid);
f20baf8e
DG
654
655 rcu_read_lock();
022d91ba 656 lttng_ht_add_unique_ulong(agent_apps_ht_by_sock, &app->node);
f20baf8e
DG
657 rcu_read_unlock();
658}
659
f20baf8e 660/*
022d91ba 661 * Delete agent application from the global hash table.
f20baf8e 662 */
022d91ba 663void agent_delete_app(struct agent_app *app)
f20baf8e
DG
664{
665 int ret;
666 struct lttng_ht_iter iter;
667
668 assert(app);
669
022d91ba 670 DBG3("Agent deleting app pid: %d and sock: %d", app->pid, app->sock->fd);
f20baf8e
DG
671
672 iter.iter.node = &app->node.node;
673 rcu_read_lock();
022d91ba 674 ret = lttng_ht_del(agent_apps_ht_by_sock, &iter);
f20baf8e
DG
675 rcu_read_unlock();
676 assert(!ret);
677}
678
679/*
022d91ba
DG
680 * Destroy a agent application object by detaching it from its corresponding
681 * UST app if one is connected by closing the socket. Finally, perform a
428de77a 682 * delayed memory reclaim.
f20baf8e 683 */
022d91ba 684void agent_destroy_app(struct agent_app *app)
f20baf8e
DG
685{
686 assert(app);
687
688 if (app->sock) {
689 app->sock->ops->close(app->sock);
690 lttcomm_destroy_sock(app->sock);
691 }
692
022d91ba 693 call_rcu(&app->node.head, destroy_app_agent_rcu);
f20baf8e
DG
694}
695
0475c50c 696/*
022d91ba 697 * Initialize an already allocated agent object.
0475c50c
DG
698 *
699 * Return 0 on success or else a negative errno value.
700 */
022d91ba 701int agent_init(struct agent *agt)
0475c50c
DG
702{
703 int ret;
704
022d91ba 705 assert(agt);
0475c50c 706
022d91ba
DG
707 agt->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
708 if (!agt->events) {
0475c50c
DG
709 ret = -ENOMEM;
710 goto error;
711 }
712
713 return 0;
714
715error:
716 return ret;
717}
718
719/*
022d91ba 720 * Create a newly allocated agent event data structure. If name is valid, it's
0475c50c
DG
721 * copied into the created event.
722 *
723 * Return a new object else NULL on error.
724 */
022d91ba 725struct agent_event *agent_create_event(const char *name,
be6a6276 726 struct lttng_filter_bytecode *filter)
0475c50c 727{
022d91ba 728 struct agent_event *event;
0475c50c 729
022d91ba 730 DBG3("Agent create new event with name %s", name);
0475c50c
DG
731
732 event = zmalloc(sizeof(*event));
733 if (!event) {
734 goto error;
735 }
736
737 if (name) {
738 strncpy(event->name, name, sizeof(event->name));
739 event->name[sizeof(event->name) - 1] = '\0';
f20baf8e 740 lttng_ht_node_init_str(&event->node, event->name);
0475c50c
DG
741 }
742
be6a6276
DG
743 if (filter) {
744 event->filter = filter;
745 }
746
0475c50c
DG
747error:
748 return event;
749}
750
751/*
022d91ba 752 * Unique add of a agent event to an agent object.
0475c50c 753 */
022d91ba 754void agent_add_event(struct agent_event *event, struct agent *agt)
0475c50c
DG
755{
756 assert(event);
022d91ba
DG
757 assert(agt);
758 assert(agt->events);
0475c50c 759
022d91ba 760 DBG3("Agent adding event %s", event->name);
0475c50c 761
f20baf8e 762 rcu_read_lock();
022d91ba 763 add_unique_agent_event(agt->events, event);
f20baf8e 764 rcu_read_unlock();
022d91ba 765 agt->being_used = 1;
0475c50c
DG
766}
767
768/*
022d91ba 769 * Find a agent event in the given agent using name.
4a4ab2c3
DG
770 *
771 * RCU read side lock MUST be acquired.
772 *
773 * Return object if found else NULL.
774 */
022d91ba
DG
775struct agent_event *agent_find_event_by_name(const char *name,
776 struct agent *agt)
4a4ab2c3
DG
777{
778 struct lttng_ht_node_str *node;
779 struct lttng_ht_iter iter;
780 struct lttng_ht *ht;
022d91ba 781 struct agent_ht_key key;
4a4ab2c3
DG
782
783 assert(name);
022d91ba
DG
784 assert(agt);
785 assert(agt->events);
4a4ab2c3 786
022d91ba 787 ht = agt->events;
4a4ab2c3
DG
788 key.name = name;
789
790 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
791 ht_match_event_by_name, &key, &iter.iter);
792 node = lttng_ht_iter_get_node_str(&iter);
793 if (node == NULL) {
794 goto error;
795 }
796
022d91ba
DG
797 DBG3("Agent event found %s by name.", name);
798 return caa_container_of(node, struct agent_event, node);
4a4ab2c3
DG
799
800error:
022d91ba 801 DBG3("Agent NOT found by name %s.", name);
4a4ab2c3
DG
802 return NULL;
803}
804
805/*
022d91ba 806 * Find a agent event in the given agent using name and loglevel.
0475c50c
DG
807 *
808 * RCU read side lock MUST be acquired.
809 *
810 * Return object if found else NULL.
811 */
022d91ba
DG
812struct agent_event *agent_find_event(const char *name, int loglevel,
813 struct agent *agt)
0475c50c
DG
814{
815 struct lttng_ht_node_str *node;
816 struct lttng_ht_iter iter;
4a4ab2c3 817 struct lttng_ht *ht;
022d91ba 818 struct agent_ht_key key;
0475c50c
DG
819
820 assert(name);
022d91ba
DG
821 assert(agt);
822 assert(agt->events);
0475c50c 823
022d91ba 824 ht = agt->events;
4a4ab2c3
DG
825 key.name = name;
826 key.loglevel = loglevel;
827
828 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
829 ht_match_event, &key, &iter.iter);
0475c50c
DG
830 node = lttng_ht_iter_get_node_str(&iter);
831 if (node == NULL) {
832 goto error;
833 }
834
022d91ba
DG
835 DBG3("Agent event found %s.", name);
836 return caa_container_of(node, struct agent_event, node);
0475c50c
DG
837
838error:
022d91ba 839 DBG3("Agent NOT found %s.", name);
0475c50c
DG
840 return NULL;
841}
842
0475c50c 843/*
022d91ba
DG
844 * Free given agent event. This event must not be globally visible at this
845 * point (only expected to be used on failure just after event creation). After
846 * this call, the pointer is not usable anymore.
0475c50c 847 */
022d91ba 848void agent_destroy_event(struct agent_event *event)
0475c50c
DG
849{
850 assert(event);
851
852 free(event);
853}
854
855/*
022d91ba 856 * Destroy an agent completely. Note that the given pointer is NOT freed
428de77a 857 * thus a reference to static or stack data can be passed to this function.
0475c50c 858 */
022d91ba 859void agent_destroy(struct agent *agt)
0475c50c
DG
860{
861 struct lttng_ht_node_str *node;
862 struct lttng_ht_iter iter;
863
022d91ba 864 assert(agt);
0475c50c 865
022d91ba 866 DBG3("Agent destroy");
0475c50c
DG
867
868 /*
869 * Just ignore if no events hash table exists. This is possible if for
022d91ba 870 * instance an agent object was allocated but not initialized.
0475c50c 871 */
022d91ba 872 if (!agt->events) {
0475c50c
DG
873 return;
874 }
875
876 rcu_read_lock();
022d91ba 877 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, node, node) {
0475c50c 878 int ret;
022d91ba 879 struct agent_event *event;
29c0fd4d
DG
880
881 /*
882 * When destroying an event, we have to try to disable it on the agent
883 * side so the event stops generating data. The return value is not
884 * important since we have to continue anyway destroying the object.
885 */
022d91ba
DG
886 event = caa_container_of(node, struct agent_event, node);
887 (void) agent_disable_event(event, agt->domain);
0475c50c 888
022d91ba 889 ret = lttng_ht_del(agt->events, &iter);
0475c50c 890 assert(!ret);
022d91ba 891 call_rcu(&node->head, destroy_event_agent_rcu);
0475c50c
DG
892 }
893 rcu_read_unlock();
894
022d91ba 895 lttng_ht_destroy(agt->events);
f20baf8e
DG
896}
897
898/*
022d91ba 899 * Initialize agent subsystem.
f20baf8e 900 */
022d91ba 901int agent_setup(void)
f20baf8e 902{
022d91ba
DG
903 agent_apps_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
904 if (!agent_apps_ht_by_sock) {
f20baf8e
DG
905 return -1;
906 }
907
908 return 0;
909}
910
911/*
022d91ba 912 * Update a agent application (given socket) using the given agent.
f20baf8e
DG
913 *
914 * Note that this function is most likely to be used with a tracing session
915 * thus the caller should make sure to hold the appropriate lock(s).
916 */
022d91ba 917void agent_update(struct agent *agt, int sock)
f20baf8e
DG
918{
919 int ret;
022d91ba
DG
920 struct agent_app *app;
921 struct agent_event *event;
f20baf8e
DG
922 struct lttng_ht_iter iter;
923
022d91ba 924 assert(agt);
f20baf8e
DG
925 assert(sock >= 0);
926
022d91ba 927 DBG("Agent updating app socket %d", sock);
f20baf8e
DG
928
929 rcu_read_lock();
022d91ba 930 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
f20baf8e
DG
931 /* Skip event if disabled. */
932 if (!event->enabled) {
933 continue;
934 }
935
022d91ba 936 app = agent_find_app_by_sock(sock);
f20baf8e
DG
937 /*
938 * We are in the registration path thus if the application is gone,
939 * there is a serious code flow error.
940 */
941 assert(app);
942
943 ret = enable_event(app, event);
944 if (ret != LTTNG_OK) {
022d91ba 945 DBG2("Agent update unable to enable event %s on app pid: %d sock %d",
f20baf8e
DG
946 event->name, app->pid, app->sock->fd);
947 /* Let's try the others here and don't assume the app is dead. */
948 continue;
949 }
950 }
951 rcu_read_unlock();
0475c50c 952}
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