Fix: UTF-8 characters may be stored on up to 4 bytes
[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
6c1c0768 19#define _LGPL_SOURCE
0475c50c 20#include <assert.h>
f20baf8e 21#include <urcu/uatomic.h>
0475c50c
DG
22
23#include <common/common.h>
022d91ba 24#include <common/sessiond-comm/agent.h>
0475c50c 25
f263b7fd
JD
26#include <common/compat/endian.h>
27
022d91ba 28#include "agent.h"
f20baf8e 29#include "ust-app.h"
0475c50c 30#include "utils.h"
23c2bd47
JG
31#include "error.h"
32
33#define AGENT_RET_CODE_INDEX(code) (code - AGENT_RET_CODE_SUCCESS)
34
35/*
36 * Human readable agent return code.
37 */
38static const char *error_string_array[] = {
39 [ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_SUCCESS) ] = "Success",
40 [ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_INVALID) ] = "Invalid command",
41 [ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_UNKNOWN_NAME) ] = "Unknown logger name",
42
43 /* Last element */
44 [ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_NR) ] = "Unknown code",
45};
46
47static
48void log_reply_code(uint32_t in_reply_ret_code)
49{
50 int level = PRINT_DBG3;
51 /*
52 * reply_ret_code and in_reply_ret_code are kept separate to have a
53 * sanitized value (used to retrieve the human readable string) and the
54 * original value which is logged as-is.
55 */
56 uint32_t reply_ret_code = in_reply_ret_code;
57
58 if (reply_ret_code < AGENT_RET_CODE_SUCCESS ||
59 reply_ret_code >= AGENT_RET_CODE_NR) {
60 reply_ret_code = AGENT_RET_CODE_NR;
61 level = PRINT_ERR;
62 }
63
64 LOG(level, "Agent replied with retcode: %s (%"PRIu32")",
65 error_string_array[AGENT_RET_CODE_INDEX(
66 reply_ret_code)],
67 in_reply_ret_code);
68}
0475c50c 69
4a4ab2c3
DG
70/*
71 * Match function for the events hash table lookup by name.
72 */
73static int ht_match_event_by_name(struct cds_lfht_node *node,
74 const void *_key)
75{
022d91ba
DG
76 struct agent_event *event;
77 const struct agent_ht_key *key;
4a4ab2c3
DG
78
79 assert(node);
80 assert(_key);
81
022d91ba 82 event = caa_container_of(node, struct agent_event, node.node);
4a4ab2c3
DG
83 key = _key;
84
85 /* Match 1 elements of the key: name. */
86
87 /* Event name */
88 if (strncmp(event->name, key->name, sizeof(event->name)) != 0) {
89 goto no_match;
90 }
91 /* Match. */
92 return 1;
93
94no_match:
95 return 0;
96}
97
98/*
99 * Match function for the events hash table lookup by name and loglevel.
100 */
101static int ht_match_event(struct cds_lfht_node *node,
102 const void *_key)
103{
022d91ba
DG
104 struct agent_event *event;
105 const struct agent_ht_key *key;
4a4ab2c3
DG
106
107 assert(node);
108 assert(_key);
109
022d91ba 110 event = caa_container_of(node, struct agent_event, node.node);
4a4ab2c3
DG
111 key = _key;
112
113 /* Match 2 elements of the key: name and loglevel. */
114
115 /* Event name */
116 if (strncmp(event->name, key->name, sizeof(event->name)) != 0) {
117 goto no_match;
118 }
119
120 if (event->loglevel != key->loglevel) {
121 if (event->loglevel_type == LTTNG_EVENT_LOGLEVEL_ALL &&
122 key->loglevel == 0 && event->loglevel == -1) {
123 goto match;
124 }
125 goto no_match;
126 }
127match:
128 return 1;
129
130no_match:
131 return 0;
132}
133
134/*
022d91ba 135 * Add unique agent event based on the event name and loglevel.
4a4ab2c3 136 */
022d91ba
DG
137static void add_unique_agent_event(struct lttng_ht *ht,
138 struct agent_event *event)
4a4ab2c3
DG
139{
140 struct cds_lfht_node *node_ptr;
022d91ba 141 struct agent_ht_key key;
4a4ab2c3
DG
142
143 assert(ht);
144 assert(ht->ht);
145 assert(event);
146
147 key.name = event->name;
148 key.loglevel = event->loglevel;
149
150 node_ptr = cds_lfht_add_unique(ht->ht,
151 ht->hash_fct(event->node.key, lttng_ht_seed),
152 ht_match_event, &key, &event->node.node);
153 assert(node_ptr == &event->node.node);
154}
155
0475c50c 156/*
022d91ba 157 * URCU delayed agent event reclaim.
0475c50c 158 */
022d91ba 159static void destroy_event_agent_rcu(struct rcu_head *head)
0475c50c
DG
160{
161 struct lttng_ht_node_str *node =
162 caa_container_of(head, struct lttng_ht_node_str, head);
022d91ba
DG
163 struct agent_event *event =
164 caa_container_of(node, struct agent_event, node);
0475c50c
DG
165
166 free(event);
167}
168
f20baf8e 169/*
022d91ba 170 * URCU delayed agent app reclaim.
f20baf8e 171 */
022d91ba 172static void destroy_app_agent_rcu(struct rcu_head *head)
f20baf8e
DG
173{
174 struct lttng_ht_node_ulong *node =
175 caa_container_of(head, struct lttng_ht_node_ulong, head);
022d91ba
DG
176 struct agent_app *app =
177 caa_container_of(node, struct agent_app, node);
f20baf8e
DG
178
179 free(app);
180}
181
182/*
022d91ba
DG
183 * Communication with the agent. Send the message header to the given socket in
184 * big endian.
f20baf8e
DG
185 *
186 * Return 0 on success or else a negative errno message of sendmsg() op.
187 */
188static int send_header(struct lttcomm_sock *sock, uint64_t data_size,
189 uint32_t cmd, uint32_t cmd_version)
190{
191 int ret;
192 ssize_t size;
022d91ba 193 struct lttcomm_agent_hdr msg;
f20baf8e
DG
194
195 assert(sock);
196
53efb85a 197 memset(&msg, 0, sizeof(msg));
f20baf8e
DG
198 msg.data_size = htobe64(data_size);
199 msg.cmd = htobe32(cmd);
200 msg.cmd_version = htobe32(cmd_version);
201
202 size = sock->ops->sendmsg(sock, &msg, sizeof(msg), 0);
203 if (size < sizeof(msg)) {
204 ret = -errno;
205 goto error;
206 }
207 ret = 0;
208
209error:
210 return ret;
211}
212
213/*
022d91ba
DG
214 * Communication call with the agent. Send the payload to the given socket. The
215 * header MUST be sent prior to this call.
f20baf8e
DG
216 *
217 * Return 0 on success or else a negative errno value of sendmsg() op.
218 */
219static int send_payload(struct lttcomm_sock *sock, void *data,
220 size_t size)
221{
222 int ret;
223 ssize_t len;
224
225 assert(sock);
226 assert(data);
227
228 len = sock->ops->sendmsg(sock, data, size, 0);
229 if (len < size) {
230 ret = -errno;
231 goto error;
232 }
233 ret = 0;
234
235error:
236 return ret;
237}
238
239/*
022d91ba
DG
240 * Communication call with the agent. Receive reply from the agent using the
241 * given socket.
f20baf8e
DG
242 *
243 * Return 0 on success or else a negative errno value from recvmsg() op.
244 */
245static int recv_reply(struct lttcomm_sock *sock, void *buf, size_t size)
246{
247 int ret;
248 ssize_t len;
249
250 assert(sock);
251 assert(buf);
252
253 len = sock->ops->recvmsg(sock, buf, size, 0);
254 if (len < size) {
255 ret = -errno;
256 goto error;
257 }
258 ret = 0;
259
260error:
261 return ret;
262}
263
3c6a091f 264/*
428de77a 265 * Internal event listing for a given app. Populate events.
3c6a091f
DG
266 *
267 * Return number of element in the list or else a negative LTTNG_ERR* code.
428de77a
MD
268 * On success, the caller is responsible for freeing the memory
269 * allocated for "events".
3c6a091f 270 */
022d91ba 271static ssize_t list_events(struct agent_app *app, struct lttng_event **events)
3c6a091f
DG
272{
273 int ret, i, len = 0, offset = 0;
274 uint32_t nb_event;
275 size_t data_size;
d84af1a4 276 uint32_t reply_ret_code;
3c6a091f 277 struct lttng_event *tmp_events = NULL;
022d91ba
DG
278 struct lttcomm_agent_list_reply *reply = NULL;
279 struct lttcomm_agent_list_reply_hdr reply_hdr;
3c6a091f
DG
280
281 assert(app);
282 assert(app->sock);
283 assert(events);
284
022d91ba 285 DBG2("Agent listing events for app pid: %d and socket %d", app->pid,
3c6a091f
DG
286 app->sock->fd);
287
022d91ba 288 ret = send_header(app->sock, 0, AGENT_CMD_LIST, 0);
3c6a091f
DG
289 if (ret < 0) {
290 goto error_io;
291 }
292
293 /* Get list header so we know how much we'll receive. */
294 ret = recv_reply(app->sock, &reply_hdr, sizeof(reply_hdr));
295 if (ret < 0) {
296 goto error_io;
297 }
298
d84af1a4
JG
299 reply_ret_code = be32toh(reply_hdr.ret_code);
300 log_reply_code(reply_ret_code);
301 switch (reply_ret_code) {
022d91ba 302 case AGENT_RET_CODE_SUCCESS:
3c6a091f
DG
303 data_size = be32toh(reply_hdr.data_size) + sizeof(*reply);
304 break;
305 default:
3bd9aaeb 306 ret = LTTNG_ERR_UNK;
3c6a091f
DG
307 goto error;
308 }
309
310 reply = zmalloc(data_size);
311 if (!reply) {
312 ret = LTTNG_ERR_NOMEM;
313 goto error;
314 }
315
316 /* Get the list with the appropriate data size. */
317 ret = recv_reply(app->sock, reply, data_size);
318 if (ret < 0) {
319 goto error_io;
320 }
321
322 nb_event = be32toh(reply->nb_event);
323 tmp_events = zmalloc(sizeof(*tmp_events) * nb_event);
324 if (!tmp_events) {
325 ret = LTTNG_ERR_NOMEM;
326 goto error;
327 }
328
329 for (i = 0; i < nb_event; i++) {
330 offset += len;
331 strncpy(tmp_events[i].name, reply->payload + offset,
332 sizeof(tmp_events[i].name));
333 tmp_events[i].pid = app->pid;
334 tmp_events[i].enabled = -1;
335 len = strlen(reply->payload + offset) + 1;
336 }
337
338 *events = tmp_events;
339
340 free(reply);
341 return nb_event;
342
343error_io:
344 ret = LTTNG_ERR_UST_LIST_FAIL;
345error:
346 free(reply);
347 free(tmp_events);
348 return -ret;
349
350}
351
f20baf8e 352/*
022d91ba
DG
353 * Internal enable agent event on a agent application. This function
354 * communicates with the agent to enable a given event.
f20baf8e
DG
355 *
356 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
357 */
022d91ba 358static int enable_event(struct agent_app *app, struct agent_event *event)
f20baf8e
DG
359{
360 int ret;
361 uint64_t data_size;
f4f9d4db 362 uint32_t reply_ret_code;
022d91ba
DG
363 struct lttcomm_agent_enable msg;
364 struct lttcomm_agent_generic_reply reply;
f20baf8e
DG
365
366 assert(app);
367 assert(app->sock);
368 assert(event);
369
022d91ba 370 DBG2("Agent enabling event %s for app pid: %d and socket %d", event->name,
f20baf8e
DG
371 app->pid, app->sock->fd);
372
373 data_size = sizeof(msg);
374
022d91ba 375 ret = send_header(app->sock, data_size, AGENT_CMD_ENABLE, 0);
f20baf8e
DG
376 if (ret < 0) {
377 goto error_io;
378 }
379
53efb85a 380 memset(&msg, 0, sizeof(msg));
b2064f54
DG
381 msg.loglevel = event->loglevel;
382 msg.loglevel_type = event->loglevel_type;
f20baf8e
DG
383 strncpy(msg.name, event->name, sizeof(msg.name));
384 ret = send_payload(app->sock, &msg, sizeof(msg));
385 if (ret < 0) {
386 goto error_io;
387 }
388
389 ret = recv_reply(app->sock, &reply, sizeof(reply));
390 if (ret < 0) {
391 goto error_io;
392 }
393
f4f9d4db
JG
394 reply_ret_code = be32toh(reply.ret_code);
395 log_reply_code(reply_ret_code);
396 switch (reply_ret_code) {
022d91ba 397 case AGENT_RET_CODE_SUCCESS:
f20baf8e 398 break;
022d91ba 399 case AGENT_RET_CODE_UNKNOWN_NAME:
f20baf8e
DG
400 ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
401 goto error;
402 default:
3bd9aaeb 403 ret = LTTNG_ERR_UNK;
f20baf8e
DG
404 goto error;
405 }
406
407 return LTTNG_OK;
408
409error_io:
410 ret = LTTNG_ERR_UST_ENABLE_FAIL;
411error:
412 return ret;
413}
414
415/*
022d91ba
DG
416 * Internal disable agent event call on a agent application. This function
417 * communicates with the agent to disable a given event.
f20baf8e
DG
418 *
419 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
420 */
022d91ba 421static int disable_event(struct agent_app *app, struct agent_event *event)
f20baf8e
DG
422{
423 int ret;
424 uint64_t data_size;
517992f8 425 uint32_t reply_ret_code;
022d91ba
DG
426 struct lttcomm_agent_disable msg;
427 struct lttcomm_agent_generic_reply reply;
f20baf8e
DG
428
429 assert(app);
430 assert(app->sock);
431 assert(event);
432
022d91ba 433 DBG2("Agent disabling event %s for app pid: %d and socket %d", event->name,
f20baf8e
DG
434 app->pid, app->sock->fd);
435
436 data_size = sizeof(msg);
437
022d91ba 438 ret = send_header(app->sock, data_size, AGENT_CMD_DISABLE, 0);
f20baf8e
DG
439 if (ret < 0) {
440 goto error_io;
441 }
442
53efb85a 443 memset(&msg, 0, sizeof(msg));
f20baf8e
DG
444 strncpy(msg.name, event->name, sizeof(msg.name));
445 ret = send_payload(app->sock, &msg, sizeof(msg));
446 if (ret < 0) {
447 goto error_io;
448 }
449
450 ret = recv_reply(app->sock, &reply, sizeof(reply));
451 if (ret < 0) {
452 goto error_io;
453 }
454
517992f8
JG
455 reply_ret_code = be32toh(reply.ret_code);
456 log_reply_code(reply_ret_code);
457 switch (reply_ret_code) {
022d91ba
DG
458 case AGENT_RET_CODE_SUCCESS:
459 break;
460 case AGENT_RET_CODE_UNKNOWN_NAME:
461 ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
462 goto error;
463 default:
3bd9aaeb 464 ret = LTTNG_ERR_UNK;
022d91ba 465 goto error;
f20baf8e
DG
466 }
467
468 return LTTNG_OK;
469
470error_io:
471 ret = LTTNG_ERR_UST_DISABLE_FAIL;
472error:
473 return ret;
474}
475
1b500e7a 476/*
022d91ba 477 * Send back the registration DONE command to a given agent application.
1b500e7a
DG
478 *
479 * Return 0 on success or else a negative value.
480 */
022d91ba 481int agent_send_registration_done(struct agent_app *app)
1b500e7a
DG
482{
483 assert(app);
484 assert(app->sock);
485
022d91ba 486 DBG("Agent sending registration done to app socket %d", app->sock->fd);
1b500e7a 487
b26d1f5c 488 return send_header(app->sock, 0, AGENT_CMD_REG_DONE, 0);
1b500e7a
DG
489}
490
f20baf8e 491/*
022d91ba 492 * Enable agent event on every agent applications registered with the session
f20baf8e
DG
493 * daemon.
494 *
495 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
496 */
fefd409b
DG
497int agent_enable_event(struct agent_event *event,
498 enum lttng_domain_type domain)
f20baf8e
DG
499{
500 int ret;
022d91ba 501 struct agent_app *app;
f20baf8e
DG
502 struct lttng_ht_iter iter;
503
504 assert(event);
505
506 rcu_read_lock();
507
022d91ba 508 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
f20baf8e 509 node.node) {
fefd409b
DG
510 if (app->domain != domain) {
511 continue;
512 }
513
022d91ba 514 /* Enable event on agent application through TCP socket. */
f20baf8e
DG
515 ret = enable_event(app, event);
516 if (ret != LTTNG_OK) {
517 goto error;
518 }
f20baf8e
DG
519 }
520
3c6a091f 521 event->enabled = 1;
f20baf8e
DG
522 ret = LTTNG_OK;
523
524error:
525 rcu_read_unlock();
526 return ret;
527}
528
529/*
022d91ba 530 * Disable agent event on every agent applications registered with the session
f20baf8e
DG
531 * daemon.
532 *
533 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
534 */
fefd409b
DG
535int agent_disable_event(struct agent_event *event,
536 enum lttng_domain_type domain)
f20baf8e 537{
f1bc0129 538 int ret = LTTNG_OK;
022d91ba 539 struct agent_app *app;
f20baf8e
DG
540 struct lttng_ht_iter iter;
541
542 assert(event);
f1bc0129
JG
543 if (!event->enabled) {
544 goto end;
545 }
f20baf8e
DG
546
547 rcu_read_lock();
548
022d91ba 549 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
f20baf8e 550 node.node) {
fefd409b
DG
551 if (app->domain != domain) {
552 continue;
553 }
554
022d91ba 555 /* Enable event on agent application through TCP socket. */
f20baf8e
DG
556 ret = disable_event(app, event);
557 if (ret != LTTNG_OK) {
558 goto error;
559 }
f20baf8e
DG
560 }
561
3c6a091f 562 event->enabled = 0;
f20baf8e
DG
563
564error:
565 rcu_read_unlock();
f1bc0129 566end:
f20baf8e
DG
567 return ret;
568}
569
570/*
022d91ba
DG
571 * Ask every agent for the list of possible event. Events is allocated with the
572 * events of every agent application.
f20baf8e
DG
573 *
574 * Return the number of events or else a negative value.
575 */
f60140a1
DG
576int agent_list_events(struct lttng_event **events,
577 enum lttng_domain_type domain)
f20baf8e
DG
578{
579 int ret;
580 size_t nbmem, count = 0;
022d91ba 581 struct agent_app *app;
aae6255e 582 struct lttng_event *tmp_events = NULL;
f20baf8e
DG
583 struct lttng_ht_iter iter;
584
585 assert(events);
586
0e115563
DG
587 DBG2("Agent listing events for domain %d", domain);
588
f20baf8e
DG
589 nbmem = UST_APP_EVENT_LIST_SIZE;
590 tmp_events = zmalloc(nbmem * sizeof(*tmp_events));
591 if (!tmp_events) {
022d91ba 592 PERROR("zmalloc agent list events");
f20baf8e
DG
593 ret = -ENOMEM;
594 goto error;
595 }
596
597 rcu_read_lock();
022d91ba 598 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
f20baf8e
DG
599 node.node) {
600 ssize_t nb_ev;
022d91ba 601 struct lttng_event *agent_events;
f20baf8e 602
f60140a1
DG
603 /* Skip domain not asked by the list. */
604 if (app->domain != domain) {
605 continue;
606 }
607
022d91ba 608 nb_ev = list_events(app, &agent_events);
f20baf8e
DG
609 if (nb_ev < 0) {
610 ret = nb_ev;
428de77a 611 goto error_unlock;
f20baf8e
DG
612 }
613
53efb85a 614 if (count + nb_ev > nbmem) {
f20baf8e 615 /* In case the realloc fails, we free the memory */
53efb85a
MD
616 struct lttng_event *new_tmp_events;
617 size_t new_nbmem;
618
619 new_nbmem = max_t(size_t, count + nb_ev, nbmem << 1);
022d91ba 620 DBG2("Reallocating agent event list from %zu to %zu entries",
53efb85a
MD
621 nbmem, new_nbmem);
622 new_tmp_events = realloc(tmp_events,
623 new_nbmem * sizeof(*new_tmp_events));
624 if (!new_tmp_events) {
022d91ba 625 PERROR("realloc agent events");
f20baf8e 626 ret = -ENOMEM;
022d91ba 627 free(agent_events);
428de77a 628 goto error_unlock;
f20baf8e 629 }
53efb85a
MD
630 /* Zero the new memory */
631 memset(new_tmp_events + nbmem, 0,
632 (new_nbmem - nbmem) * sizeof(*new_tmp_events));
633 nbmem = new_nbmem;
634 tmp_events = new_tmp_events;
f20baf8e 635 }
022d91ba 636 memcpy(tmp_events + count, agent_events,
53efb85a 637 nb_ev * sizeof(*tmp_events));
022d91ba 638 free(agent_events);
f20baf8e
DG
639 count += nb_ev;
640 }
641 rcu_read_unlock();
642
643 ret = count;
644 *events = tmp_events;
aae6255e 645 return ret;
f20baf8e 646
428de77a
MD
647error_unlock:
648 rcu_read_unlock();
f20baf8e 649error:
aae6255e 650 free(tmp_events);
f20baf8e
DG
651 return ret;
652}
653
654/*
022d91ba 655 * Create a agent app object using the given PID.
f20baf8e
DG
656 *
657 * Return newly allocated object or else NULL on error.
658 */
fefd409b
DG
659struct agent_app *agent_create_app(pid_t pid, enum lttng_domain_type domain,
660 struct lttcomm_sock *sock)
f20baf8e 661{
022d91ba 662 struct agent_app *app;
f20baf8e
DG
663
664 assert(sock);
665
666 app = zmalloc(sizeof(*app));
667 if (!app) {
022d91ba 668 PERROR("zmalloc agent create");
f20baf8e
DG
669 goto error;
670 }
671
672 app->pid = pid;
fefd409b 673 app->domain = domain;
f20baf8e 674 app->sock = sock;
f20baf8e
DG
675 lttng_ht_node_init_ulong(&app->node, (unsigned long) app->sock->fd);
676
677error:
678 return app;
679}
680
681/*
022d91ba 682 * Lookup agent app by socket in the global hash table.
f20baf8e
DG
683 *
684 * RCU read side lock MUST be acquired.
685 *
686 * Return object if found else NULL.
687 */
022d91ba 688struct agent_app *agent_find_app_by_sock(int sock)
f20baf8e
DG
689{
690 struct lttng_ht_node_ulong *node;
691 struct lttng_ht_iter iter;
022d91ba 692 struct agent_app *app;
f20baf8e
DG
693
694 assert(sock >= 0);
695
022d91ba 696 lttng_ht_lookup(agent_apps_ht_by_sock, (void *)((unsigned long) sock), &iter);
f20baf8e
DG
697 node = lttng_ht_iter_get_node_ulong(&iter);
698 if (node == NULL) {
699 goto error;
700 }
022d91ba 701 app = caa_container_of(node, struct agent_app, node);
f20baf8e 702
022d91ba 703 DBG3("Agent app pid %d found by sock %d.", app->pid, sock);
f20baf8e
DG
704 return app;
705
706error:
022d91ba 707 DBG3("Agent app NOT found by sock %d.", sock);
f20baf8e
DG
708 return NULL;
709}
710
711/*
022d91ba 712 * Add agent application object to the global hash table.
f20baf8e 713 */
022d91ba 714void agent_add_app(struct agent_app *app)
f20baf8e
DG
715{
716 assert(app);
717
022d91ba 718 DBG3("Agent adding app sock: %d and pid: %d to ht", app->sock->fd, app->pid);
022d91ba 719 lttng_ht_add_unique_ulong(agent_apps_ht_by_sock, &app->node);
f20baf8e
DG
720}
721
f20baf8e 722/*
022d91ba 723 * Delete agent application from the global hash table.
d558f236
JG
724 *
725 * rcu_read_lock() must be held by the caller.
f20baf8e 726 */
022d91ba 727void agent_delete_app(struct agent_app *app)
f20baf8e
DG
728{
729 int ret;
730 struct lttng_ht_iter iter;
731
732 assert(app);
733
022d91ba 734 DBG3("Agent deleting app pid: %d and sock: %d", app->pid, app->sock->fd);
f20baf8e
DG
735
736 iter.iter.node = &app->node.node;
022d91ba 737 ret = lttng_ht_del(agent_apps_ht_by_sock, &iter);
f20baf8e
DG
738 assert(!ret);
739}
740
741/*
e785906c 742 * Destroy an agent application object by detaching it from its corresponding
022d91ba 743 * UST app if one is connected by closing the socket. Finally, perform a
428de77a 744 * delayed memory reclaim.
f20baf8e 745 */
022d91ba 746void agent_destroy_app(struct agent_app *app)
f20baf8e
DG
747{
748 assert(app);
749
750 if (app->sock) {
751 app->sock->ops->close(app->sock);
752 lttcomm_destroy_sock(app->sock);
753 }
754
022d91ba 755 call_rcu(&app->node.head, destroy_app_agent_rcu);
f20baf8e
DG
756}
757
0475c50c 758/*
022d91ba 759 * Initialize an already allocated agent object.
0475c50c
DG
760 *
761 * Return 0 on success or else a negative errno value.
762 */
022d91ba 763int agent_init(struct agent *agt)
0475c50c
DG
764{
765 int ret;
766
022d91ba 767 assert(agt);
0475c50c 768
022d91ba
DG
769 agt->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
770 if (!agt->events) {
0475c50c
DG
771 ret = -ENOMEM;
772 goto error;
773 }
fefd409b 774 lttng_ht_node_init_u64(&agt->node, agt->domain);
0475c50c
DG
775
776 return 0;
777
778error:
779 return ret;
780}
781
fefd409b
DG
782/*
783 * Add agent object to the given hash table.
784 */
785void agent_add(struct agent *agt, struct lttng_ht *ht)
786{
787 assert(agt);
788 assert(ht);
789
790 DBG3("Agent adding from domain %d", agt->domain);
791
fefd409b 792 lttng_ht_add_unique_u64(ht, &agt->node);
fefd409b
DG
793}
794
795/*
796 * Create an agent object for the given domain.
797 *
798 * Return the allocated agent or NULL on error.
799 */
800struct agent *agent_create(enum lttng_domain_type domain)
801{
802 int ret;
803 struct agent *agt;
804
3b5f70d4 805 agt = zmalloc(sizeof(struct agent));
fefd409b
DG
806 if (!agt) {
807 goto error;
808 }
809 agt->domain = domain;
810
811 ret = agent_init(agt);
812 if (ret < 0) {
813 free(agt);
988ae332 814 agt = NULL;
fefd409b
DG
815 goto error;
816 }
817
818error:
819 return agt;
820}
821
0475c50c 822/*
022d91ba 823 * Create a newly allocated agent event data structure. If name is valid, it's
0475c50c
DG
824 * copied into the created event.
825 *
826 * Return a new object else NULL on error.
827 */
022d91ba 828struct agent_event *agent_create_event(const char *name,
be6a6276 829 struct lttng_filter_bytecode *filter)
0475c50c 830{
022d91ba 831 struct agent_event *event;
0475c50c 832
022d91ba 833 DBG3("Agent create new event with name %s", name);
0475c50c
DG
834
835 event = zmalloc(sizeof(*event));
836 if (!event) {
837 goto error;
838 }
839
840 if (name) {
841 strncpy(event->name, name, sizeof(event->name));
842 event->name[sizeof(event->name) - 1] = '\0';
f20baf8e 843 lttng_ht_node_init_str(&event->node, event->name);
0475c50c
DG
844 }
845
be6a6276
DG
846 if (filter) {
847 event->filter = filter;
848 }
849
0475c50c
DG
850error:
851 return event;
852}
853
854/*
022d91ba 855 * Unique add of a agent event to an agent object.
0475c50c 856 */
022d91ba 857void agent_add_event(struct agent_event *event, struct agent *agt)
0475c50c
DG
858{
859 assert(event);
022d91ba
DG
860 assert(agt);
861 assert(agt->events);
0475c50c 862
022d91ba 863 DBG3("Agent adding event %s", event->name);
022d91ba 864 add_unique_agent_event(agt->events, event);
022d91ba 865 agt->being_used = 1;
0475c50c
DG
866}
867
868/*
022d91ba 869 * Find a agent event in the given agent using name.
4a4ab2c3
DG
870 *
871 * RCU read side lock MUST be acquired.
872 *
873 * Return object if found else NULL.
874 */
022d91ba
DG
875struct agent_event *agent_find_event_by_name(const char *name,
876 struct agent *agt)
4a4ab2c3
DG
877{
878 struct lttng_ht_node_str *node;
879 struct lttng_ht_iter iter;
880 struct lttng_ht *ht;
022d91ba 881 struct agent_ht_key key;
4a4ab2c3
DG
882
883 assert(name);
022d91ba
DG
884 assert(agt);
885 assert(agt->events);
4a4ab2c3 886
022d91ba 887 ht = agt->events;
4a4ab2c3
DG
888 key.name = name;
889
890 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
891 ht_match_event_by_name, &key, &iter.iter);
892 node = lttng_ht_iter_get_node_str(&iter);
893 if (node == NULL) {
894 goto error;
895 }
896
022d91ba
DG
897 DBG3("Agent event found %s by name.", name);
898 return caa_container_of(node, struct agent_event, node);
4a4ab2c3
DG
899
900error:
022d91ba 901 DBG3("Agent NOT found by name %s.", name);
4a4ab2c3
DG
902 return NULL;
903}
904
905/*
022d91ba 906 * Find a agent event in the given agent using name and loglevel.
0475c50c
DG
907 *
908 * RCU read side lock MUST be acquired.
909 *
910 * Return object if found else NULL.
911 */
022d91ba
DG
912struct agent_event *agent_find_event(const char *name, int loglevel,
913 struct agent *agt)
0475c50c
DG
914{
915 struct lttng_ht_node_str *node;
916 struct lttng_ht_iter iter;
4a4ab2c3 917 struct lttng_ht *ht;
022d91ba 918 struct agent_ht_key key;
0475c50c
DG
919
920 assert(name);
022d91ba
DG
921 assert(agt);
922 assert(agt->events);
0475c50c 923
022d91ba 924 ht = agt->events;
4a4ab2c3
DG
925 key.name = name;
926 key.loglevel = loglevel;
927
928 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
929 ht_match_event, &key, &iter.iter);
0475c50c
DG
930 node = lttng_ht_iter_get_node_str(&iter);
931 if (node == NULL) {
932 goto error;
933 }
934
022d91ba
DG
935 DBG3("Agent event found %s.", name);
936 return caa_container_of(node, struct agent_event, node);
0475c50c
DG
937
938error:
a51e817b 939 DBG3("Agent event NOT found %s.", name);
0475c50c
DG
940 return NULL;
941}
942
0475c50c 943/*
022d91ba
DG
944 * Free given agent event. This event must not be globally visible at this
945 * point (only expected to be used on failure just after event creation). After
946 * this call, the pointer is not usable anymore.
0475c50c 947 */
022d91ba 948void agent_destroy_event(struct agent_event *event)
0475c50c
DG
949{
950 assert(event);
951
971da06a 952 free(event->filter);
8404118c 953 free(event->filter_expression);
0475c50c
DG
954 free(event);
955}
956
957/*
022d91ba 958 * Destroy an agent completely. Note that the given pointer is NOT freed
428de77a 959 * thus a reference to static or stack data can be passed to this function.
0475c50c 960 */
022d91ba 961void agent_destroy(struct agent *agt)
0475c50c
DG
962{
963 struct lttng_ht_node_str *node;
964 struct lttng_ht_iter iter;
965
022d91ba 966 assert(agt);
0475c50c 967
022d91ba 968 DBG3("Agent destroy");
0475c50c 969
0475c50c 970 rcu_read_lock();
022d91ba 971 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, node, node) {
0475c50c 972 int ret;
022d91ba 973 struct agent_event *event;
29c0fd4d
DG
974
975 /*
976 * When destroying an event, we have to try to disable it on the agent
977 * side so the event stops generating data. The return value is not
978 * important since we have to continue anyway destroying the object.
979 */
022d91ba
DG
980 event = caa_container_of(node, struct agent_event, node);
981 (void) agent_disable_event(event, agt->domain);
0475c50c 982
022d91ba 983 ret = lttng_ht_del(agt->events, &iter);
0475c50c 984 assert(!ret);
022d91ba 985 call_rcu(&node->head, destroy_event_agent_rcu);
0475c50c
DG
986 }
987 rcu_read_unlock();
988
f8be902b 989 ht_cleanup_push(agt->events);
f20baf8e
DG
990}
991
992/*
6a4e4039 993 * Allocate agent_apps_ht_by_sock.
f20baf8e 994 */
6a4e4039 995int agent_app_ht_alloc(void)
f20baf8e 996{
6a4e4039
JG
997 int ret = 0;
998
022d91ba
DG
999 agent_apps_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1000 if (!agent_apps_ht_by_sock) {
6a4e4039 1001 ret = -1;
f20baf8e
DG
1002 }
1003
6a4e4039
JG
1004 return ret;
1005}
1006
1007/*
1008 * Destroy a agent application by socket.
1009 */
1010void agent_destroy_app_by_sock(int sock)
1011{
1012 struct agent_app *app;
1013
1014 assert(sock >= 0);
1015
1016 /*
1017 * Not finding an application is a very important error that should NEVER
1018 * happen. The hash table deletion is ONLY done through this call when the
1019 * main sessiond thread is torn down.
1020 */
1021 rcu_read_lock();
1022 app = agent_find_app_by_sock(sock);
1023 assert(app);
1024
1025 /* RCU read side lock is assumed to be held by this function. */
1026 agent_delete_app(app);
1027
1028 /* The application is freed in a RCU call but the socket is closed here. */
1029 agent_destroy_app(app);
1030 rcu_read_unlock();
1031}
1032
1033/*
1034 * Clean-up the agent app hash table and destroy it.
1035 */
1036void agent_app_ht_clean(void)
1037{
1038 struct lttng_ht_node_ulong *node;
1039 struct lttng_ht_iter iter;
1040
a433283e
JG
1041 if (!agent_apps_ht_by_sock) {
1042 return;
1043 }
6a4e4039
JG
1044 rcu_read_lock();
1045 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, node, node) {
1046 struct agent_app *app;
1047
1048 app = caa_container_of(node, struct agent_app, node);
1049 agent_destroy_app_by_sock(app->sock->fd);
1050 }
1051 rcu_read_unlock();
1052
1053 lttng_ht_destroy(agent_apps_ht_by_sock);
f20baf8e
DG
1054}
1055
1056/*
022d91ba 1057 * Update a agent application (given socket) using the given agent.
f20baf8e
DG
1058 *
1059 * Note that this function is most likely to be used with a tracing session
1060 * thus the caller should make sure to hold the appropriate lock(s).
1061 */
022d91ba 1062void agent_update(struct agent *agt, int sock)
f20baf8e
DG
1063{
1064 int ret;
022d91ba
DG
1065 struct agent_app *app;
1066 struct agent_event *event;
f20baf8e
DG
1067 struct lttng_ht_iter iter;
1068
022d91ba 1069 assert(agt);
f20baf8e
DG
1070 assert(sock >= 0);
1071
022d91ba 1072 DBG("Agent updating app socket %d", sock);
f20baf8e
DG
1073
1074 rcu_read_lock();
022d91ba 1075 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
f20baf8e
DG
1076 /* Skip event if disabled. */
1077 if (!event->enabled) {
1078 continue;
1079 }
1080
022d91ba 1081 app = agent_find_app_by_sock(sock);
f20baf8e
DG
1082 /*
1083 * We are in the registration path thus if the application is gone,
1084 * there is a serious code flow error.
1085 */
1086 assert(app);
1087
1088 ret = enable_event(app, event);
1089 if (ret != LTTNG_OK) {
022d91ba 1090 DBG2("Agent update unable to enable event %s on app pid: %d sock %d",
f20baf8e
DG
1091 event->name, app->pid, app->sock->fd);
1092 /* Let's try the others here and don't assume the app is dead. */
1093 continue;
1094 }
1095 }
1096 rcu_read_unlock();
0475c50c 1097}
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