b2608a186f83095b9faf20fd58a222eb4f2b0283
[lttng-tools.git] / src / bin / lttng-sessiond / agent.c
1 /*
2 * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
3 * Copyright (C) 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License, version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 51
16 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _LGPL_SOURCE
20 #include <assert.h>
21 #include <urcu/uatomic.h>
22 #include <urcu/rculist.h>
23
24 #include <common/common.h>
25 #include <common/sessiond-comm/agent.h>
26
27 #include <common/compat/endian.h>
28
29 #include "agent.h"
30 #include "ust-app.h"
31 #include "utils.h"
32 #include "error.h"
33
34 #define AGENT_RET_CODE_INDEX(code) (code - AGENT_RET_CODE_SUCCESS)
35
36 /*
37 * Agent application context representation.
38 */
39 struct agent_app_ctx {
40 char *provider_name;
41 char *ctx_name;
42
43 /* agent_app_ctx are part of the agent app_ctx_list. */
44 struct cds_list_head list_node;
45
46 /* For call_rcu teardown. */
47 struct rcu_head rcu_node;
48 };
49
50 /*
51 * Human readable agent return code.
52 */
53 static const char *error_string_array[] = {
54 [ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_SUCCESS) ] = "Success",
55 [ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_INVALID) ] = "Invalid command",
56 [ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_UNKNOWN_NAME) ] = "Unknown logger name",
57
58 /* Last element */
59 [ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_NR) ] = "Unknown code",
60 };
61
62 static
63 void log_reply_code(uint32_t in_reply_ret_code)
64 {
65 int level = PRINT_DBG3;
66 /*
67 * reply_ret_code and in_reply_ret_code are kept separate to have a
68 * sanitized value (used to retrieve the human readable string) and the
69 * original value which is logged as-is.
70 */
71 uint32_t reply_ret_code = in_reply_ret_code;
72
73 if (reply_ret_code < AGENT_RET_CODE_SUCCESS ||
74 reply_ret_code >= AGENT_RET_CODE_NR) {
75 reply_ret_code = AGENT_RET_CODE_NR;
76 level = PRINT_ERR;
77 }
78
79 LOG(level, "Agent replied with retcode: %s (%"PRIu32")",
80 error_string_array[AGENT_RET_CODE_INDEX(
81 reply_ret_code)],
82 in_reply_ret_code);
83 }
84
85 /*
86 * Match function for the events hash table lookup by name.
87 */
88 static int ht_match_event_by_name(struct cds_lfht_node *node,
89 const void *_key)
90 {
91 struct agent_event *event;
92 const struct agent_ht_key *key;
93
94 assert(node);
95 assert(_key);
96
97 event = caa_container_of(node, struct agent_event, node.node);
98 key = _key;
99
100 /* Match 1 elements of the key: name. */
101
102 /* Event name */
103 if (strncmp(event->name, key->name, sizeof(event->name)) != 0) {
104 goto no_match;
105 }
106 /* Match. */
107 return 1;
108
109 no_match:
110 return 0;
111 }
112
113 /*
114 * Match function for the events hash table lookup by name and loglevel.
115 */
116 static int ht_match_event(struct cds_lfht_node *node,
117 const void *_key)
118 {
119 struct agent_event *event;
120 const struct agent_ht_key *key;
121 int ll_match;
122
123 assert(node);
124 assert(_key);
125
126 event = caa_container_of(node, struct agent_event, node.node);
127 key = _key;
128
129 /* Match 2 elements of the key: name and loglevel. */
130
131 /* Event name */
132 if (strncmp(event->name, key->name, sizeof(event->name)) != 0) {
133 goto no_match;
134 }
135
136 /* Event loglevel value and type. */
137 ll_match = loglevels_match(event->loglevel_type,
138 event->loglevel_value, key->loglevel_type,
139 key->loglevel_value, LTTNG_EVENT_LOGLEVEL_ALL);
140
141 if (!ll_match) {
142 goto no_match;
143 }
144
145 /* Filter expression */
146 if (strncmp(event->filter_expression, key->filter_expression,
147 strlen(event->filter_expression)) != 0) {
148 goto no_match;
149 }
150
151 return 1;
152
153 no_match:
154 return 0;
155 }
156
157 /*
158 * Add unique agent event based on the event name and loglevel.
159 */
160 static void add_unique_agent_event(struct lttng_ht *ht,
161 struct agent_event *event)
162 {
163 struct cds_lfht_node *node_ptr;
164 struct agent_ht_key key;
165
166 assert(ht);
167 assert(ht->ht);
168 assert(event);
169
170 key.name = event->name;
171 key.loglevel_value = event->loglevel_value;
172 key.loglevel_type = event->loglevel_type;
173 key.filter_expression = event->filter_expression;
174
175 node_ptr = cds_lfht_add_unique(ht->ht,
176 ht->hash_fct(event->node.key, lttng_ht_seed),
177 ht_match_event, &key, &event->node.node);
178 assert(node_ptr == &event->node.node);
179 }
180
181 /*
182 * URCU delayed agent event reclaim.
183 */
184 static void destroy_event_agent_rcu(struct rcu_head *head)
185 {
186 struct lttng_ht_node_str *node =
187 caa_container_of(head, struct lttng_ht_node_str, head);
188 struct agent_event *event =
189 caa_container_of(node, struct agent_event, node);
190
191 agent_destroy_event(event);
192 }
193
194 /*
195 * URCU delayed agent app reclaim.
196 */
197 static void destroy_app_agent_rcu(struct rcu_head *head)
198 {
199 struct lttng_ht_node_ulong *node =
200 caa_container_of(head, struct lttng_ht_node_ulong, head);
201 struct agent_app *app =
202 caa_container_of(node, struct agent_app, node);
203
204 free(app);
205 }
206
207 /*
208 * Communication with the agent. Send the message header to the given socket in
209 * big endian.
210 *
211 * Return 0 on success or else a negative errno message of sendmsg() op.
212 */
213 static int send_header(struct lttcomm_sock *sock, uint64_t data_size,
214 uint32_t cmd, uint32_t cmd_version)
215 {
216 int ret;
217 ssize_t size;
218 struct lttcomm_agent_hdr msg;
219
220 assert(sock);
221
222 memset(&msg, 0, sizeof(msg));
223 msg.data_size = htobe64(data_size);
224 msg.cmd = htobe32(cmd);
225 msg.cmd_version = htobe32(cmd_version);
226
227 size = sock->ops->sendmsg(sock, &msg, sizeof(msg), 0);
228 if (size < sizeof(msg)) {
229 ret = -errno;
230 goto error;
231 }
232 ret = 0;
233
234 error:
235 return ret;
236 }
237
238 /*
239 * Communication call with the agent. Send the payload to the given socket. The
240 * header MUST be sent prior to this call.
241 *
242 * Return 0 on success or else a negative errno value of sendmsg() op.
243 */
244 static int send_payload(struct lttcomm_sock *sock, const void *data,
245 size_t size)
246 {
247 int ret;
248 ssize_t len;
249
250 assert(sock);
251 assert(data);
252
253 len = sock->ops->sendmsg(sock, data, size, 0);
254 if (len < size) {
255 ret = -errno;
256 goto error;
257 }
258 ret = 0;
259
260 error:
261 return ret;
262 }
263
264 /*
265 * Communication call with the agent. Receive reply from the agent using the
266 * given socket.
267 *
268 * Return 0 on success or else a negative errno value from recvmsg() op.
269 */
270 static int recv_reply(struct lttcomm_sock *sock, void *buf, size_t size)
271 {
272 int ret;
273 ssize_t len;
274
275 assert(sock);
276 assert(buf);
277
278 len = sock->ops->recvmsg(sock, buf, size, 0);
279 if (len < size) {
280 ret = -errno;
281 goto error;
282 }
283 ret = 0;
284
285 error:
286 return ret;
287 }
288
289 /*
290 * Internal event listing for a given app. Populate events.
291 *
292 * Return number of element in the list or else a negative LTTNG_ERR* code.
293 * On success, the caller is responsible for freeing the memory
294 * allocated for "events".
295 */
296 static ssize_t list_events(struct agent_app *app, struct lttng_event **events)
297 {
298 int ret, i, len = 0, offset = 0;
299 uint32_t nb_event;
300 size_t data_size;
301 uint32_t reply_ret_code;
302 struct lttng_event *tmp_events = NULL;
303 struct lttcomm_agent_list_reply *reply = NULL;
304 struct lttcomm_agent_list_reply_hdr reply_hdr;
305
306 assert(app);
307 assert(app->sock);
308 assert(events);
309
310 DBG2("Agent listing events for app pid: %d and socket %d", app->pid,
311 app->sock->fd);
312
313 ret = send_header(app->sock, 0, AGENT_CMD_LIST, 0);
314 if (ret < 0) {
315 goto error_io;
316 }
317
318 /* Get list header so we know how much we'll receive. */
319 ret = recv_reply(app->sock, &reply_hdr, sizeof(reply_hdr));
320 if (ret < 0) {
321 goto error_io;
322 }
323
324 reply_ret_code = be32toh(reply_hdr.ret_code);
325 log_reply_code(reply_ret_code);
326 switch (reply_ret_code) {
327 case AGENT_RET_CODE_SUCCESS:
328 data_size = be32toh(reply_hdr.data_size) + sizeof(*reply);
329 break;
330 default:
331 ret = LTTNG_ERR_UNK;
332 goto error;
333 }
334
335 reply = zmalloc(data_size);
336 if (!reply) {
337 ret = LTTNG_ERR_NOMEM;
338 goto error;
339 }
340
341 /* Get the list with the appropriate data size. */
342 ret = recv_reply(app->sock, reply, data_size);
343 if (ret < 0) {
344 goto error_io;
345 }
346
347 nb_event = be32toh(reply->nb_event);
348 tmp_events = zmalloc(sizeof(*tmp_events) * nb_event);
349 if (!tmp_events) {
350 ret = LTTNG_ERR_NOMEM;
351 goto error;
352 }
353
354 for (i = 0; i < nb_event; i++) {
355 offset += len;
356 strncpy(tmp_events[i].name, reply->payload + offset,
357 sizeof(tmp_events[i].name));
358 tmp_events[i].pid = app->pid;
359 tmp_events[i].enabled = -1;
360 len = strlen(reply->payload + offset) + 1;
361 }
362
363 *events = tmp_events;
364
365 free(reply);
366 return nb_event;
367
368 error_io:
369 ret = LTTNG_ERR_UST_LIST_FAIL;
370 error:
371 free(reply);
372 free(tmp_events);
373 return -ret;
374
375 }
376
377 /*
378 * Internal enable agent event on a agent application. This function
379 * communicates with the agent to enable a given event.
380 *
381 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
382 */
383 static int enable_event(struct agent_app *app, struct agent_event *event)
384 {
385 int ret;
386 char *bytes_to_send;
387 uint64_t data_size;
388 size_t filter_expression_length;
389 uint32_t reply_ret_code;
390 struct lttcomm_agent_enable_event msg;
391 struct lttcomm_agent_generic_reply reply;
392
393 assert(app);
394 assert(app->sock);
395 assert(event);
396
397 DBG2("Agent enabling event %s for app pid: %d and socket %d", event->name,
398 app->pid, app->sock->fd);
399
400 /*
401 * Calculate the payload's size, which is the fixed-size struct followed
402 * by the variable-length filter expression (+1 for the ending \0).
403 */
404 if (!event->filter_expression) {
405 filter_expression_length = 0;
406 } else {
407 filter_expression_length = strlen(event->filter_expression) + 1;
408 }
409 data_size = sizeof(msg) + filter_expression_length;
410
411 ret = send_header(app->sock, data_size, AGENT_CMD_ENABLE, 0);
412 if (ret < 0) {
413 goto error_io;
414 }
415
416 memset(&msg, 0, sizeof(msg));
417 msg.loglevel_value = htobe32(event->loglevel_value);
418 msg.loglevel_type = htobe32(event->loglevel_type);
419 strncpy(msg.name, event->name, sizeof(msg.name));
420 msg.filter_expression_length = htobe32(filter_expression_length);
421
422 bytes_to_send = zmalloc(data_size);
423 if (!bytes_to_send) {
424 ret = LTTNG_ERR_NOMEM;
425 goto error;
426 }
427
428 memcpy(bytes_to_send, &msg, sizeof(msg));
429 if (filter_expression_length > 0) {
430 memcpy(bytes_to_send + sizeof(msg), event->filter_expression,
431 filter_expression_length);
432 }
433
434 ret = send_payload(app->sock, bytes_to_send, data_size);
435 free(bytes_to_send);
436 if (ret < 0) {
437 goto error_io;
438 }
439
440 ret = recv_reply(app->sock, &reply, sizeof(reply));
441 if (ret < 0) {
442 goto error_io;
443 }
444
445 reply_ret_code = be32toh(reply.ret_code);
446 log_reply_code(reply_ret_code);
447 switch (reply_ret_code) {
448 case AGENT_RET_CODE_SUCCESS:
449 break;
450 case AGENT_RET_CODE_UNKNOWN_NAME:
451 ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
452 goto error;
453 default:
454 ret = LTTNG_ERR_UNK;
455 goto error;
456 }
457
458 return LTTNG_OK;
459
460 error_io:
461 ret = LTTNG_ERR_UST_ENABLE_FAIL;
462 error:
463 return ret;
464 }
465
466 /*
467 * Send Pascal-style string. Size is sent as a 32-bit big endian integer.
468 */
469 static
470 int send_pstring(struct lttcomm_sock *sock, const char *str, uint32_t len)
471 {
472 int ret;
473 uint32_t len_be;
474
475 len_be = htobe32(len);
476 ret = send_payload(sock, &len_be, sizeof(len_be));
477 if (ret) {
478 goto end;
479 }
480
481 ret = send_payload(sock, str, len);
482 if (ret) {
483 goto end;
484 }
485 end:
486 return ret;
487 }
488
489 /*
490 * Internal enable application context on an agent application. This function
491 * communicates with the agent to enable a given application context.
492 *
493 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
494 */
495 static int app_context_op(struct agent_app *app,
496 struct agent_app_ctx *ctx, enum lttcomm_agent_command cmd)
497 {
498 int ret;
499 uint32_t reply_ret_code;
500 struct lttcomm_agent_generic_reply reply;
501 size_t app_ctx_provider_name_len, app_ctx_name_len, data_size;
502
503 assert(app);
504 assert(app->sock);
505 assert(ctx);
506 assert(cmd == AGENT_CMD_APP_CTX_ENABLE ||
507 cmd == AGENT_CMD_APP_CTX_DISABLE);
508
509 DBG2("Agent %s application %s:%s for app pid: %d and socket %d",
510 cmd == AGENT_CMD_APP_CTX_ENABLE ? "enabling" : "disabling",
511 ctx->provider_name, ctx->ctx_name,
512 app->pid, app->sock->fd);
513
514 /*
515 * Calculate the payload's size, which consists of the size (u32, BE)
516 * of the provider name, the NULL-terminated provider name string, the
517 * size (u32, BE) of the context name, followed by the NULL-terminated
518 * context name string.
519 */
520 app_ctx_provider_name_len = strlen(ctx->provider_name) + 1;
521 app_ctx_name_len = strlen(ctx->ctx_name) + 1;
522 data_size = sizeof(uint32_t) + app_ctx_provider_name_len +
523 sizeof(uint32_t) + app_ctx_name_len;
524
525 ret = send_header(app->sock, data_size, cmd, 0);
526 if (ret < 0) {
527 goto error_io;
528 }
529
530 if (app_ctx_provider_name_len > UINT32_MAX ||
531 app_ctx_name_len > UINT32_MAX) {
532 ERR("Application context name > MAX_UINT32");
533 ret = LTTNG_ERR_INVALID;
534 goto error;
535 }
536
537 ret = send_pstring(app->sock, ctx->provider_name,
538 (uint32_t) app_ctx_provider_name_len);
539 if (ret < 0) {
540 goto error_io;
541 }
542
543 ret = send_pstring(app->sock, ctx->ctx_name,
544 (uint32_t) app_ctx_name_len);
545 if (ret < 0) {
546 goto error_io;
547 }
548
549 ret = recv_reply(app->sock, &reply, sizeof(reply));
550 if (ret < 0) {
551 goto error_io;
552 }
553
554 reply_ret_code = be32toh(reply.ret_code);
555 log_reply_code(reply_ret_code);
556 switch (reply_ret_code) {
557 case AGENT_RET_CODE_SUCCESS:
558 break;
559 default:
560 ret = LTTNG_ERR_UNK;
561 goto error;
562 }
563
564 return LTTNG_OK;
565
566 error_io:
567 ret = LTTNG_ERR_UST_ENABLE_FAIL;
568 error:
569 return ret;
570 }
571
572 /*
573 * Internal disable agent event call on a agent application. This function
574 * communicates with the agent to disable a given event.
575 *
576 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
577 */
578 static int disable_event(struct agent_app *app, struct agent_event *event)
579 {
580 int ret;
581 uint64_t data_size;
582 uint32_t reply_ret_code;
583 struct lttcomm_agent_disable_event msg;
584 struct lttcomm_agent_generic_reply reply;
585
586 assert(app);
587 assert(app->sock);
588 assert(event);
589
590 DBG2("Agent disabling event %s for app pid: %d and socket %d", event->name,
591 app->pid, app->sock->fd);
592
593 data_size = sizeof(msg);
594
595 ret = send_header(app->sock, data_size, AGENT_CMD_DISABLE, 0);
596 if (ret < 0) {
597 goto error_io;
598 }
599
600 memset(&msg, 0, sizeof(msg));
601 strncpy(msg.name, event->name, sizeof(msg.name));
602 ret = send_payload(app->sock, &msg, sizeof(msg));
603 if (ret < 0) {
604 goto error_io;
605 }
606
607 ret = recv_reply(app->sock, &reply, sizeof(reply));
608 if (ret < 0) {
609 goto error_io;
610 }
611
612 reply_ret_code = be32toh(reply.ret_code);
613 log_reply_code(reply_ret_code);
614 switch (reply_ret_code) {
615 case AGENT_RET_CODE_SUCCESS:
616 break;
617 case AGENT_RET_CODE_UNKNOWN_NAME:
618 ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
619 goto error;
620 default:
621 ret = LTTNG_ERR_UNK;
622 goto error;
623 }
624
625 return LTTNG_OK;
626
627 error_io:
628 ret = LTTNG_ERR_UST_DISABLE_FAIL;
629 error:
630 return ret;
631 }
632
633 /*
634 * Send back the registration DONE command to a given agent application.
635 *
636 * Return 0 on success or else a negative value.
637 */
638 int agent_send_registration_done(struct agent_app *app)
639 {
640 assert(app);
641 assert(app->sock);
642
643 DBG("Agent sending registration done to app socket %d", app->sock->fd);
644
645 return send_header(app->sock, 0, AGENT_CMD_REG_DONE, 0);
646 }
647
648 /*
649 * Enable agent event on every agent applications registered with the session
650 * daemon.
651 *
652 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
653 */
654 int agent_enable_event(struct agent_event *event,
655 enum lttng_domain_type domain)
656 {
657 int ret;
658 struct agent_app *app;
659 struct lttng_ht_iter iter;
660
661 assert(event);
662
663 rcu_read_lock();
664
665 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
666 node.node) {
667 if (app->domain != domain) {
668 continue;
669 }
670
671 /* Enable event on agent application through TCP socket. */
672 ret = enable_event(app, event);
673 if (ret != LTTNG_OK) {
674 goto error;
675 }
676 }
677
678 event->enabled = 1;
679 ret = LTTNG_OK;
680
681 error:
682 rcu_read_unlock();
683 return ret;
684 }
685
686 static
687 void destroy_app_ctx(struct agent_app_ctx *ctx)
688 {
689 free(ctx->provider_name);
690 free(ctx->ctx_name);
691 free(ctx);
692 }
693
694 static
695 struct agent_app_ctx *create_app_ctx(struct lttng_event_context *ctx)
696 {
697 struct agent_app_ctx *agent_ctx = NULL;
698
699 if (!ctx) {
700 goto end;
701 }
702
703 assert(ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT);
704 agent_ctx = zmalloc(sizeof(*ctx));
705 if (!agent_ctx) {
706 goto end;
707 }
708
709 agent_ctx->provider_name = strdup(ctx->u.app_ctx.provider_name);
710 agent_ctx->ctx_name = strdup(ctx->u.app_ctx.ctx_name);
711 if (!agent_ctx->provider_name || !agent_ctx->ctx_name) {
712 destroy_app_ctx(agent_ctx);
713 agent_ctx = NULL;
714 }
715 end:
716 return agent_ctx;
717 }
718
719 /*
720 * Enable agent context on every agent applications registered with the session
721 * daemon.
722 *
723 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
724 */
725 int agent_enable_context(struct lttng_event_context *ctx,
726 enum lttng_domain_type domain)
727 {
728 int ret;
729 struct agent_app *app;
730 struct lttng_ht_iter iter;
731
732 assert(ctx);
733 if (ctx->ctx != LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
734 ret = LTTNG_ERR_INVALID;
735 goto error;
736 }
737
738 rcu_read_lock();
739
740 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
741 node.node) {
742 struct agent_app_ctx *agent_ctx;
743
744 if (app->domain != domain) {
745 continue;
746 }
747
748 agent_ctx = create_app_ctx(ctx);
749 if (!agent_ctx) {
750 goto error_unlock;
751 }
752
753 /* Enable event on agent application through TCP socket. */
754 ret = app_context_op(app, agent_ctx, AGENT_CMD_APP_CTX_ENABLE);
755 if (ret != LTTNG_OK) {
756 destroy_app_ctx(agent_ctx);
757 goto error_unlock;
758 }
759 }
760
761 ret = LTTNG_OK;
762
763 error_unlock:
764 rcu_read_unlock();
765 error:
766 return ret;
767 }
768
769 /*
770 * Disable agent event on every agent application registered with the session
771 * daemon.
772 *
773 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
774 */
775 int agent_disable_event(struct agent_event *event,
776 enum lttng_domain_type domain)
777 {
778 int ret = LTTNG_OK;
779 struct agent_app *app;
780 struct lttng_ht_iter iter;
781
782 assert(event);
783 if (!event->enabled) {
784 goto end;
785 }
786
787 rcu_read_lock();
788
789 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
790 node.node) {
791 if (app->domain != domain) {
792 continue;
793 }
794
795 /* Enable event on agent application through TCP socket. */
796 ret = disable_event(app, event);
797 if (ret != LTTNG_OK) {
798 goto error;
799 }
800 }
801
802 event->enabled = 0;
803
804 error:
805 rcu_read_unlock();
806 end:
807 return ret;
808 }
809
810 /*
811 * Disable agent context on every agent application registered with the session
812 * daemon.
813 *
814 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
815 */
816 int disable_context(struct agent_app_ctx *ctx, enum lttng_domain_type domain)
817 {
818 int ret = LTTNG_OK;
819 struct agent_app *app;
820 struct lttng_ht_iter iter;
821
822 assert(ctx);
823
824 rcu_read_lock();
825 DBG2("Disabling agent application context %s:%s",
826 ctx->provider_name, ctx->ctx_name);
827 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
828 node.node) {
829 if (app->domain != domain) {
830 continue;
831 }
832
833 ret = app_context_op(app, ctx, AGENT_CMD_APP_CTX_DISABLE);
834 if (ret != LTTNG_OK) {
835 goto end;
836 }
837 }
838 end:
839 rcu_read_unlock();
840 return ret;
841 }
842
843 /*
844 * Ask every agent for the list of possible event. Events is allocated with the
845 * events of every agent application.
846 *
847 * Return the number of events or else a negative value.
848 */
849 int agent_list_events(struct lttng_event **events,
850 enum lttng_domain_type domain)
851 {
852 int ret;
853 size_t nbmem, count = 0;
854 struct agent_app *app;
855 struct lttng_event *tmp_events = NULL;
856 struct lttng_ht_iter iter;
857
858 assert(events);
859
860 DBG2("Agent listing events for domain %d", domain);
861
862 nbmem = UST_APP_EVENT_LIST_SIZE;
863 tmp_events = zmalloc(nbmem * sizeof(*tmp_events));
864 if (!tmp_events) {
865 PERROR("zmalloc agent list events");
866 ret = -ENOMEM;
867 goto error;
868 }
869
870 rcu_read_lock();
871 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
872 node.node) {
873 ssize_t nb_ev;
874 struct lttng_event *agent_events;
875
876 /* Skip domain not asked by the list. */
877 if (app->domain != domain) {
878 continue;
879 }
880
881 nb_ev = list_events(app, &agent_events);
882 if (nb_ev < 0) {
883 ret = nb_ev;
884 goto error_unlock;
885 }
886
887 if (count + nb_ev > nbmem) {
888 /* In case the realloc fails, we free the memory */
889 struct lttng_event *new_tmp_events;
890 size_t new_nbmem;
891
892 new_nbmem = max_t(size_t, count + nb_ev, nbmem << 1);
893 DBG2("Reallocating agent event list from %zu to %zu entries",
894 nbmem, new_nbmem);
895 new_tmp_events = realloc(tmp_events,
896 new_nbmem * sizeof(*new_tmp_events));
897 if (!new_tmp_events) {
898 PERROR("realloc agent events");
899 ret = -ENOMEM;
900 free(agent_events);
901 goto error_unlock;
902 }
903 /* Zero the new memory */
904 memset(new_tmp_events + nbmem, 0,
905 (new_nbmem - nbmem) * sizeof(*new_tmp_events));
906 nbmem = new_nbmem;
907 tmp_events = new_tmp_events;
908 }
909 memcpy(tmp_events + count, agent_events,
910 nb_ev * sizeof(*tmp_events));
911 free(agent_events);
912 count += nb_ev;
913 }
914 rcu_read_unlock();
915
916 ret = count;
917 *events = tmp_events;
918 return ret;
919
920 error_unlock:
921 rcu_read_unlock();
922 error:
923 free(tmp_events);
924 return ret;
925 }
926
927 /*
928 * Create a agent app object using the given PID.
929 *
930 * Return newly allocated object or else NULL on error.
931 */
932 struct agent_app *agent_create_app(pid_t pid, enum lttng_domain_type domain,
933 struct lttcomm_sock *sock)
934 {
935 struct agent_app *app;
936
937 assert(sock);
938
939 app = zmalloc(sizeof(*app));
940 if (!app) {
941 PERROR("zmalloc agent create");
942 goto error;
943 }
944
945 app->pid = pid;
946 app->domain = domain;
947 app->sock = sock;
948 lttng_ht_node_init_ulong(&app->node, (unsigned long) app->sock->fd);
949
950 error:
951 return app;
952 }
953
954 /*
955 * Lookup agent app by socket in the global hash table.
956 *
957 * RCU read side lock MUST be acquired.
958 *
959 * Return object if found else NULL.
960 */
961 struct agent_app *agent_find_app_by_sock(int sock)
962 {
963 struct lttng_ht_node_ulong *node;
964 struct lttng_ht_iter iter;
965 struct agent_app *app;
966
967 assert(sock >= 0);
968
969 lttng_ht_lookup(agent_apps_ht_by_sock, (void *)((unsigned long) sock), &iter);
970 node = lttng_ht_iter_get_node_ulong(&iter);
971 if (node == NULL) {
972 goto error;
973 }
974 app = caa_container_of(node, struct agent_app, node);
975
976 DBG3("Agent app pid %d found by sock %d.", app->pid, sock);
977 return app;
978
979 error:
980 DBG3("Agent app NOT found by sock %d.", sock);
981 return NULL;
982 }
983
984 /*
985 * Add agent application object to the global hash table.
986 */
987 void agent_add_app(struct agent_app *app)
988 {
989 assert(app);
990
991 DBG3("Agent adding app sock: %d and pid: %d to ht", app->sock->fd, app->pid);
992 lttng_ht_add_unique_ulong(agent_apps_ht_by_sock, &app->node);
993 }
994
995 /*
996 * Delete agent application from the global hash table.
997 *
998 * rcu_read_lock() must be held by the caller.
999 */
1000 void agent_delete_app(struct agent_app *app)
1001 {
1002 int ret;
1003 struct lttng_ht_iter iter;
1004
1005 assert(app);
1006
1007 DBG3("Agent deleting app pid: %d and sock: %d", app->pid, app->sock->fd);
1008
1009 iter.iter.node = &app->node.node;
1010 ret = lttng_ht_del(agent_apps_ht_by_sock, &iter);
1011 assert(!ret);
1012 }
1013
1014 /*
1015 * Destroy an agent application object by detaching it from its corresponding
1016 * UST app if one is connected by closing the socket. Finally, perform a
1017 * delayed memory reclaim.
1018 */
1019 void agent_destroy_app(struct agent_app *app)
1020 {
1021 assert(app);
1022
1023 if (app->sock) {
1024 app->sock->ops->close(app->sock);
1025 lttcomm_destroy_sock(app->sock);
1026 }
1027
1028 call_rcu(&app->node.head, destroy_app_agent_rcu);
1029 }
1030
1031 /*
1032 * Initialize an already allocated agent object.
1033 *
1034 * Return 0 on success or else a negative errno value.
1035 */
1036 int agent_init(struct agent *agt)
1037 {
1038 int ret;
1039
1040 assert(agt);
1041
1042 agt->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1043 if (!agt->events) {
1044 ret = -ENOMEM;
1045 goto error;
1046 }
1047 lttng_ht_node_init_u64(&agt->node, agt->domain);
1048
1049 CDS_INIT_LIST_HEAD(&agt->app_ctx_list);
1050 return 0;
1051
1052 error:
1053 return ret;
1054 }
1055
1056 /*
1057 * Add agent object to the given hash table.
1058 */
1059 void agent_add(struct agent *agt, struct lttng_ht *ht)
1060 {
1061 assert(agt);
1062 assert(ht);
1063
1064 DBG3("Agent adding from domain %d", agt->domain);
1065
1066 lttng_ht_add_unique_u64(ht, &agt->node);
1067 }
1068
1069 /*
1070 * Create an agent object for the given domain.
1071 *
1072 * Return the allocated agent or NULL on error.
1073 */
1074 struct agent *agent_create(enum lttng_domain_type domain)
1075 {
1076 int ret;
1077 struct agent *agt;
1078
1079 agt = zmalloc(sizeof(struct agent));
1080 if (!agt) {
1081 goto error;
1082 }
1083 agt->domain = domain;
1084
1085 ret = agent_init(agt);
1086 if (ret < 0) {
1087 free(agt);
1088 agt = NULL;
1089 goto error;
1090 }
1091
1092 error:
1093 return agt;
1094 }
1095
1096 /*
1097 * Create a newly allocated agent event data structure.
1098 * Ownership of filter_expression is taken.
1099 *
1100 * Return a new object else NULL on error.
1101 */
1102 struct agent_event *agent_create_event(const char *name,
1103 enum lttng_loglevel_type loglevel_type, int loglevel_value,
1104 struct lttng_filter_bytecode *filter, char *filter_expression)
1105 {
1106 struct agent_event *event = NULL;
1107
1108 DBG3("Agent create new event with name %s, loglevel type %d, \
1109 loglevel value %d and filter %s",
1110 name, loglevel_type, loglevel_value,
1111 filter_expression ? filter_expression : "NULL");
1112
1113 if (!name) {
1114 ERR("Failed to create agent event; no name provided.");
1115 goto error;
1116 }
1117
1118 event = zmalloc(sizeof(*event));
1119 if (!event) {
1120 goto error;
1121 }
1122
1123 strncpy(event->name, name, sizeof(event->name));
1124 event->name[sizeof(event->name) - 1] = '\0';
1125 lttng_ht_node_init_str(&event->node, event->name);
1126
1127 event->loglevel_value = loglevel_value;
1128 event->loglevel_type = loglevel_type;
1129 event->filter = filter;
1130 event->filter_expression = filter_expression;
1131 error:
1132 return event;
1133 }
1134
1135 /*
1136 * Unique add of a agent event to an agent object.
1137 */
1138 void agent_add_event(struct agent_event *event, struct agent *agt)
1139 {
1140 assert(event);
1141 assert(agt);
1142 assert(agt->events);
1143
1144 DBG3("Agent adding event %s", event->name);
1145 add_unique_agent_event(agt->events, event);
1146 agt->being_used = 1;
1147 }
1148
1149 /*
1150 * Unique add of a agent context to an agent object.
1151 */
1152 int agent_add_context(struct lttng_event_context *ctx, struct agent *agt)
1153 {
1154 int ret = LTTNG_OK;
1155 struct agent_app_ctx *agent_ctx = NULL;
1156
1157 assert(ctx);
1158 assert(agt);
1159 assert(agt->events);
1160 assert(ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT);
1161
1162 agent_ctx = create_app_ctx(ctx);
1163 if (!agent_ctx) {
1164 ret = LTTNG_ERR_NOMEM;
1165 goto end;
1166 }
1167
1168 DBG3("Agent adding context %s:%s", ctx->u.app_ctx.provider_name,
1169 ctx->u.app_ctx.ctx_name);
1170 cds_list_add_tail_rcu(&agent_ctx->list_node, &agt->app_ctx_list);
1171 end:
1172 return ret;
1173 }
1174
1175 /*
1176 * Find multiple agent events sharing the given name.
1177 *
1178 * RCU read side lock MUST be acquired. It must be held for the
1179 * duration of the iteration.
1180 *
1181 * Sets the given iterator.
1182 */
1183 void agent_find_events_by_name(const char *name, struct agent *agt,
1184 struct lttng_ht_iter* iter)
1185 {
1186 struct lttng_ht *ht;
1187 struct agent_ht_key key;
1188
1189 assert(name);
1190 assert(agt);
1191 assert(agt->events);
1192 assert(iter);
1193
1194 ht = agt->events;
1195 key.name = name;
1196
1197 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1198 ht_match_event_by_name, &key, &iter->iter);
1199 }
1200
1201 /*
1202 * Get the next agent event duplicate by name. This should be called
1203 * after a call to agent_find_events_by_name() to iterate on events.
1204 *
1205 * The RCU read lock must be held during the iteration and for as long
1206 * as the object the iterator points to remains in use.
1207 */
1208 void agent_event_next_duplicate(const char *name,
1209 struct agent *agt, struct lttng_ht_iter* iter)
1210 {
1211 struct agent_ht_key key;
1212
1213 key.name = name;
1214
1215 cds_lfht_next_duplicate(agt->events->ht, ht_match_event_by_name,
1216 &key, &iter->iter);
1217 }
1218
1219 /*
1220 * Find a agent event in the given agent using name, loglevel and filter.
1221 *
1222 * RCU read side lock MUST be acquired. It must be kept for as long as
1223 * the returned agent_event is used.
1224 *
1225 * Return object if found else NULL.
1226 */
1227 struct agent_event *agent_find_event(const char *name,
1228 enum lttng_loglevel_type loglevel_type, int loglevel_value,
1229 char *filter_expression, struct agent *agt)
1230 {
1231 struct lttng_ht_node_str *node;
1232 struct lttng_ht_iter iter;
1233 struct lttng_ht *ht;
1234 struct agent_ht_key key;
1235
1236 assert(name);
1237 assert(agt);
1238 assert(agt->events);
1239
1240 ht = agt->events;
1241 key.name = name;
1242 key.loglevel_value = loglevel_value;
1243 key.loglevel_type = loglevel_type;
1244 key.filter_expression = filter_expression;
1245
1246 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1247 ht_match_event, &key, &iter.iter);
1248 node = lttng_ht_iter_get_node_str(&iter);
1249 if (node == NULL) {
1250 goto error;
1251 }
1252
1253 DBG3("Agent event found %s.", name);
1254 return caa_container_of(node, struct agent_event, node);
1255
1256 error:
1257 DBG3("Agent event NOT found %s.", name);
1258 return NULL;
1259 }
1260
1261 /*
1262 * Free given agent event. This event must not be globally visible at this
1263 * point (only expected to be used on failure just after event creation). After
1264 * this call, the pointer is not usable anymore.
1265 */
1266 void agent_destroy_event(struct agent_event *event)
1267 {
1268 assert(event);
1269
1270 free(event->filter);
1271 free(event->filter_expression);
1272 free(event->exclusion);
1273 free(event);
1274 }
1275
1276 static
1277 void destroy_app_ctx_rcu(struct rcu_head *head)
1278 {
1279 struct agent_app_ctx *ctx =
1280 caa_container_of(head, struct agent_app_ctx, rcu_node);
1281
1282 destroy_app_ctx(ctx);
1283 }
1284
1285 /*
1286 * Destroy an agent completely.
1287 */
1288 void agent_destroy(struct agent *agt)
1289 {
1290 struct lttng_ht_node_str *node;
1291 struct lttng_ht_iter iter;
1292 struct agent_app_ctx *ctx;
1293
1294 assert(agt);
1295
1296 DBG3("Agent destroy");
1297
1298 rcu_read_lock();
1299 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, node, node) {
1300 int ret;
1301 struct agent_event *event;
1302
1303 /*
1304 * When destroying an event, we have to try to disable it on the
1305 * agent side so the event stops generating data. The return
1306 * value is not important since we have to continue anyway
1307 * destroying the object.
1308 */
1309 event = caa_container_of(node, struct agent_event, node);
1310 (void) agent_disable_event(event, agt->domain);
1311
1312 ret = lttng_ht_del(agt->events, &iter);
1313 assert(!ret);
1314 call_rcu(&node->head, destroy_event_agent_rcu);
1315 }
1316
1317 cds_list_for_each_entry_rcu(ctx, &agt->app_ctx_list, list_node) {
1318 (void) disable_context(ctx, agt->domain);
1319 cds_list_del(&ctx->list_node);
1320 call_rcu(&ctx->rcu_node, destroy_app_ctx_rcu);
1321 }
1322 rcu_read_unlock();
1323 ht_cleanup_push(agt->events);
1324 free(agt);
1325 }
1326
1327 /*
1328 * Allocate agent_apps_ht_by_sock.
1329 */
1330 int agent_app_ht_alloc(void)
1331 {
1332 int ret = 0;
1333
1334 agent_apps_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1335 if (!agent_apps_ht_by_sock) {
1336 ret = -1;
1337 }
1338
1339 return ret;
1340 }
1341
1342 /*
1343 * Destroy a agent application by socket.
1344 */
1345 void agent_destroy_app_by_sock(int sock)
1346 {
1347 struct agent_app *app;
1348
1349 assert(sock >= 0);
1350
1351 /*
1352 * Not finding an application is a very important error that should NEVER
1353 * happen. The hash table deletion is ONLY done through this call when the
1354 * main sessiond thread is torn down.
1355 */
1356 rcu_read_lock();
1357 app = agent_find_app_by_sock(sock);
1358 assert(app);
1359
1360 /* RCU read side lock is assumed to be held by this function. */
1361 agent_delete_app(app);
1362
1363 /* The application is freed in a RCU call but the socket is closed here. */
1364 agent_destroy_app(app);
1365 rcu_read_unlock();
1366 }
1367
1368 /*
1369 * Clean-up the agent app hash table and destroy it.
1370 */
1371 void agent_app_ht_clean(void)
1372 {
1373 struct lttng_ht_node_ulong *node;
1374 struct lttng_ht_iter iter;
1375
1376 if (!agent_apps_ht_by_sock) {
1377 return;
1378 }
1379 rcu_read_lock();
1380 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, node, node) {
1381 struct agent_app *app;
1382
1383 app = caa_container_of(node, struct agent_app, node);
1384 agent_destroy_app_by_sock(app->sock->fd);
1385 }
1386 rcu_read_unlock();
1387
1388 lttng_ht_destroy(agent_apps_ht_by_sock);
1389 }
1390
1391 /*
1392 * Update a agent application (given socket) using the given agent.
1393 *
1394 * Note that this function is most likely to be used with a tracing session
1395 * thus the caller should make sure to hold the appropriate lock(s).
1396 */
1397 void agent_update(struct agent *agt, int sock)
1398 {
1399 int ret;
1400 struct agent_app *app;
1401 struct agent_event *event;
1402 struct lttng_ht_iter iter;
1403 struct agent_app_ctx *ctx;
1404
1405 assert(agt);
1406 assert(sock >= 0);
1407
1408 DBG("Agent updating app socket %d", sock);
1409
1410 rcu_read_lock();
1411 app = agent_find_app_by_sock(sock);
1412 /*
1413 * We are in the registration path thus if the application is gone,
1414 * there is a serious code flow error.
1415 */
1416 assert(app);
1417 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
1418 /* Skip event if disabled. */
1419 if (!event->enabled) {
1420 continue;
1421 }
1422
1423 ret = enable_event(app, event);
1424 if (ret != LTTNG_OK) {
1425 DBG2("Agent update unable to enable event %s on app pid: %d sock %d",
1426 event->name, app->pid, app->sock->fd);
1427 /* Let's try the others here and don't assume the app is dead. */
1428 continue;
1429 }
1430 }
1431
1432 cds_list_for_each_entry_rcu(ctx, &agt->app_ctx_list, list_node) {
1433 ret = app_context_op(app, ctx, AGENT_CMD_APP_CTX_ENABLE);
1434 if (ret != LTTNG_OK) {
1435 DBG2("Agent update unable to add application context %s:%s on app pid: %d sock %d",
1436 ctx->provider_name, ctx->ctx_name,
1437 app->pid, app->sock->fd);
1438 continue;
1439 }
1440 }
1441
1442 rcu_read_unlock();
1443 }
This page took 0.095643 seconds and 3 git commands to generate.