1926b0820fc808f4076e12b8110a4ce5fe34cbae
[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 * SPDX-License-Identifier: GPL-2.0-only
6 *
7 */
8
9 #define _LGPL_SOURCE
10 #include <assert.h>
11 #include <urcu/uatomic.h>
12 #include <urcu/rculist.h>
13
14 #include <common/common.h>
15 #include <common/sessiond-comm/agent.h>
16
17 #include <common/compat/endian.h>
18
19 #include "agent.h"
20 #include "ust-app.h"
21 #include "utils.h"
22 #include "common/error.h"
23
24 #define AGENT_RET_CODE_INDEX(code) (code - AGENT_RET_CODE_SUCCESS)
25
26 /*
27 * Agent application context representation.
28 */
29 struct agent_app_ctx {
30 char *provider_name;
31 char *ctx_name;
32
33 /* agent_app_ctx are part of the agent app_ctx_list. */
34 struct cds_list_head list_node;
35
36 /* For call_rcu teardown. */
37 struct rcu_head rcu_node;
38 };
39
40 /*
41 * Human readable agent return code.
42 */
43 static const char *error_string_array[] = {
44 [ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_SUCCESS) ] = "Success",
45 [ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_INVALID) ] = "Invalid command",
46 [ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_UNKNOWN_NAME) ] = "Unknown logger name",
47
48 /* Last element */
49 [ AGENT_RET_CODE_INDEX(AGENT_RET_CODE_NR) ] = "Unknown code",
50 };
51
52 static
53 void log_reply_code(uint32_t in_reply_ret_code)
54 {
55 int level = PRINT_DBG3;
56 /*
57 * reply_ret_code and in_reply_ret_code are kept separate to have a
58 * sanitized value (used to retrieve the human readable string) and the
59 * original value which is logged as-is.
60 */
61 uint32_t reply_ret_code = in_reply_ret_code;
62
63 if (reply_ret_code < AGENT_RET_CODE_SUCCESS ||
64 reply_ret_code >= AGENT_RET_CODE_NR) {
65 reply_ret_code = AGENT_RET_CODE_NR;
66 level = PRINT_ERR;
67 }
68
69 LOG(level, "Agent replied with retcode: %s (%"PRIu32")",
70 error_string_array[AGENT_RET_CODE_INDEX(
71 reply_ret_code)],
72 in_reply_ret_code);
73 }
74
75 /*
76 * Match function for the events hash table lookup by name.
77 */
78 static int ht_match_event_by_name(struct cds_lfht_node *node,
79 const void *_key)
80 {
81 struct agent_event *event;
82 const struct agent_ht_key *key;
83
84 assert(node);
85 assert(_key);
86
87 event = caa_container_of(node, struct agent_event, node.node);
88 key = _key;
89
90 /* Match 1 elements of the key: name. */
91
92 /* Event name */
93 if (strncmp(event->name, key->name, sizeof(event->name)) != 0) {
94 goto no_match;
95 }
96 /* Match. */
97 return 1;
98
99 no_match:
100 return 0;
101 }
102
103 /*
104 * Match function for the events hash table lookup by name and loglevel.
105 */
106 static int ht_match_event(struct cds_lfht_node *node,
107 const void *_key)
108 {
109 struct agent_event *event;
110 const struct agent_ht_key *key;
111 int ll_match;
112
113 assert(node);
114 assert(_key);
115
116 event = caa_container_of(node, struct agent_event, node.node);
117 key = _key;
118
119 /* Match 2 elements of the key: name and loglevel. */
120
121 /* Event name */
122 if (strncmp(event->name, key->name, sizeof(event->name)) != 0) {
123 goto no_match;
124 }
125
126 /* Event loglevel value and type. */
127 ll_match = loglevels_match(event->loglevel_type,
128 event->loglevel_value, key->loglevel_type,
129 key->loglevel_value, LTTNG_EVENT_LOGLEVEL_ALL);
130
131 if (!ll_match) {
132 goto no_match;
133 }
134
135 /* Filter expression */
136 if (!!event->filter_expression != !!key->filter_expression) {
137 /* One has a filter expression, the other does not */
138 goto no_match;
139 }
140
141 if (event->filter_expression) {
142 if (strncmp(event->filter_expression, key->filter_expression,
143 strlen(event->filter_expression)) != 0) {
144 goto no_match;
145 }
146 }
147
148 return 1;
149
150 no_match:
151 return 0;
152 }
153
154 /*
155 * Add unique agent event based on the event name and loglevel.
156 */
157 static void add_unique_agent_event(struct lttng_ht *ht,
158 struct agent_event *event)
159 {
160 struct cds_lfht_node *node_ptr;
161 struct agent_ht_key key;
162
163 assert(ht);
164 assert(ht->ht);
165 assert(event);
166
167 key.name = event->name;
168 key.loglevel_value = event->loglevel_value;
169 key.loglevel_type = event->loglevel_type;
170 key.filter_expression = event->filter_expression;
171
172 node_ptr = cds_lfht_add_unique(ht->ht,
173 ht->hash_fct(event->node.key, lttng_ht_seed),
174 ht_match_event, &key, &event->node.node);
175 assert(node_ptr == &event->node.node);
176 }
177
178 /*
179 * URCU delayed agent event reclaim.
180 */
181 static void destroy_event_agent_rcu(struct rcu_head *head)
182 {
183 struct lttng_ht_node_str *node =
184 caa_container_of(head, struct lttng_ht_node_str, head);
185 struct agent_event *event =
186 caa_container_of(node, struct agent_event, node);
187
188 agent_destroy_event(event);
189 }
190
191 /*
192 * URCU delayed agent app reclaim.
193 */
194 static void destroy_app_agent_rcu(struct rcu_head *head)
195 {
196 struct lttng_ht_node_ulong *node =
197 caa_container_of(head, struct lttng_ht_node_ulong, head);
198 struct agent_app *app =
199 caa_container_of(node, struct agent_app, node);
200
201 free(app);
202 }
203
204 /*
205 * Communication with the agent. Send the message header to the given socket in
206 * big endian.
207 *
208 * Return 0 on success or else a negative errno message of sendmsg() op.
209 */
210 static int send_header(struct lttcomm_sock *sock, uint64_t data_size,
211 uint32_t cmd, uint32_t cmd_version)
212 {
213 int ret;
214 ssize_t size;
215 struct lttcomm_agent_hdr msg;
216
217 assert(sock);
218
219 memset(&msg, 0, sizeof(msg));
220 msg.data_size = htobe64(data_size);
221 msg.cmd = htobe32(cmd);
222 msg.cmd_version = htobe32(cmd_version);
223
224 size = sock->ops->sendmsg(sock, &msg, sizeof(msg), 0);
225 if (size < sizeof(msg)) {
226 ret = -errno;
227 goto error;
228 }
229 ret = 0;
230
231 error:
232 return ret;
233 }
234
235 /*
236 * Communication call with the agent. Send the payload to the given socket. The
237 * header MUST be sent prior to this call.
238 *
239 * Return 0 on success or else a negative errno value of sendmsg() op.
240 */
241 static int send_payload(struct lttcomm_sock *sock, const void *data,
242 size_t size)
243 {
244 int ret;
245 ssize_t len;
246
247 assert(sock);
248 assert(data);
249
250 len = sock->ops->sendmsg(sock, data, size, 0);
251 if (len < size) {
252 ret = -errno;
253 goto error;
254 }
255 ret = 0;
256
257 error:
258 return ret;
259 }
260
261 /*
262 * Communication call with the agent. Receive reply from the agent using the
263 * given socket.
264 *
265 * Return 0 on success or else a negative errno value from recvmsg() op.
266 */
267 static int recv_reply(struct lttcomm_sock *sock, void *buf, size_t size)
268 {
269 int ret;
270 ssize_t len;
271
272 assert(sock);
273 assert(buf);
274
275 len = sock->ops->recvmsg(sock, buf, size, 0);
276 if (len < size) {
277 ret = -errno;
278 goto error;
279 }
280 ret = 0;
281
282 error:
283 return ret;
284 }
285
286 /*
287 * Internal event listing for a given app. Populate events.
288 *
289 * Return number of element in the list or else a negative LTTNG_ERR* code.
290 * On success, the caller is responsible for freeing the memory
291 * allocated for "events".
292 */
293 static ssize_t list_events(struct agent_app *app, struct lttng_event **events)
294 {
295 int ret, i, len = 0, offset = 0;
296 uint32_t nb_event;
297 size_t data_size;
298 uint32_t reply_ret_code;
299 struct lttng_event *tmp_events = NULL;
300 struct lttcomm_agent_list_reply *reply = NULL;
301 struct lttcomm_agent_list_reply_hdr reply_hdr;
302
303 assert(app);
304 assert(app->sock);
305 assert(events);
306
307 DBG2("Agent listing events for app pid: %d and socket %d", app->pid,
308 app->sock->fd);
309
310 ret = send_header(app->sock, 0, AGENT_CMD_LIST, 0);
311 if (ret < 0) {
312 goto error_io;
313 }
314
315 /* Get list header so we know how much we'll receive. */
316 ret = recv_reply(app->sock, &reply_hdr, sizeof(reply_hdr));
317 if (ret < 0) {
318 goto error_io;
319 }
320
321 reply_ret_code = be32toh(reply_hdr.ret_code);
322 log_reply_code(reply_ret_code);
323 switch (reply_ret_code) {
324 case AGENT_RET_CODE_SUCCESS:
325 data_size = be32toh(reply_hdr.data_size) + sizeof(*reply);
326 break;
327 default:
328 ret = LTTNG_ERR_UNK;
329 goto error;
330 }
331
332 reply = zmalloc(data_size);
333 if (!reply) {
334 ret = LTTNG_ERR_NOMEM;
335 goto error;
336 }
337
338 /* Get the list with the appropriate data size. */
339 ret = recv_reply(app->sock, reply, data_size);
340 if (ret < 0) {
341 goto error_io;
342 }
343
344 nb_event = be32toh(reply->nb_event);
345 tmp_events = zmalloc(sizeof(*tmp_events) * nb_event);
346 if (!tmp_events) {
347 ret = LTTNG_ERR_NOMEM;
348 goto error;
349 }
350
351 for (i = 0; i < nb_event; i++) {
352 offset += len;
353 if (lttng_strncpy(tmp_events[i].name, reply->payload + offset,
354 sizeof(tmp_events[i].name))) {
355 ret = LTTNG_ERR_INVALID;
356 goto error;
357 }
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 memset(&msg, 0, sizeof(msg));
412 msg.loglevel_value = htobe32(event->loglevel_value);
413 msg.loglevel_type = htobe32(event->loglevel_type);
414 if (lttng_strncpy(msg.name, event->name, sizeof(msg.name))) {
415 ret = LTTNG_ERR_INVALID;
416 goto error;
417 }
418 msg.filter_expression_length = htobe32(filter_expression_length);
419
420 ret = send_header(app->sock, data_size, AGENT_CMD_ENABLE, 0);
421 if (ret < 0) {
422 goto error_io;
423 }
424
425 bytes_to_send = zmalloc(data_size);
426 if (!bytes_to_send) {
427 ret = LTTNG_ERR_NOMEM;
428 goto error;
429 }
430
431 memcpy(bytes_to_send, &msg, sizeof(msg));
432 if (filter_expression_length > 0) {
433 memcpy(bytes_to_send + sizeof(msg), event->filter_expression,
434 filter_expression_length);
435 }
436
437 ret = send_payload(app->sock, bytes_to_send, data_size);
438 free(bytes_to_send);
439 if (ret < 0) {
440 goto error_io;
441 }
442
443 ret = recv_reply(app->sock, &reply, sizeof(reply));
444 if (ret < 0) {
445 goto error_io;
446 }
447
448 reply_ret_code = be32toh(reply.ret_code);
449 log_reply_code(reply_ret_code);
450 switch (reply_ret_code) {
451 case AGENT_RET_CODE_SUCCESS:
452 break;
453 case AGENT_RET_CODE_UNKNOWN_NAME:
454 ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
455 goto error;
456 default:
457 ret = LTTNG_ERR_UNK;
458 goto error;
459 }
460
461 return LTTNG_OK;
462
463 error_io:
464 ret = LTTNG_ERR_UST_ENABLE_FAIL;
465 error:
466 return ret;
467 }
468
469 /*
470 * Send Pascal-style string. Size is sent as a 32-bit big endian integer.
471 */
472 static
473 int send_pstring(struct lttcomm_sock *sock, const char *str, uint32_t len)
474 {
475 int ret;
476 uint32_t len_be;
477
478 len_be = htobe32(len);
479 ret = send_payload(sock, &len_be, sizeof(len_be));
480 if (ret) {
481 goto end;
482 }
483
484 ret = send_payload(sock, str, len);
485 if (ret) {
486 goto end;
487 }
488 end:
489 return ret;
490 }
491
492 /*
493 * Internal enable application context on an agent application. This function
494 * communicates with the agent to enable a given application context.
495 *
496 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
497 */
498 static int app_context_op(struct agent_app *app,
499 struct agent_app_ctx *ctx, enum lttcomm_agent_command cmd)
500 {
501 int ret;
502 uint32_t reply_ret_code;
503 struct lttcomm_agent_generic_reply reply;
504 size_t app_ctx_provider_name_len, app_ctx_name_len, data_size;
505
506 assert(app);
507 assert(app->sock);
508 assert(ctx);
509 assert(cmd == AGENT_CMD_APP_CTX_ENABLE ||
510 cmd == AGENT_CMD_APP_CTX_DISABLE);
511
512 DBG2("Agent %s application %s:%s for app pid: %d and socket %d",
513 cmd == AGENT_CMD_APP_CTX_ENABLE ? "enabling" : "disabling",
514 ctx->provider_name, ctx->ctx_name,
515 app->pid, app->sock->fd);
516
517 /*
518 * Calculate the payload's size, which consists of the size (u32, BE)
519 * of the provider name, the NULL-terminated provider name string, the
520 * size (u32, BE) of the context name, followed by the NULL-terminated
521 * context name string.
522 */
523 app_ctx_provider_name_len = strlen(ctx->provider_name) + 1;
524 app_ctx_name_len = strlen(ctx->ctx_name) + 1;
525 data_size = sizeof(uint32_t) + app_ctx_provider_name_len +
526 sizeof(uint32_t) + app_ctx_name_len;
527
528 ret = send_header(app->sock, data_size, cmd, 0);
529 if (ret < 0) {
530 goto error_io;
531 }
532
533 if (app_ctx_provider_name_len > UINT32_MAX ||
534 app_ctx_name_len > UINT32_MAX) {
535 ERR("Application context name > MAX_UINT32");
536 ret = LTTNG_ERR_INVALID;
537 goto error;
538 }
539
540 ret = send_pstring(app->sock, ctx->provider_name,
541 (uint32_t) app_ctx_provider_name_len);
542 if (ret < 0) {
543 goto error_io;
544 }
545
546 ret = send_pstring(app->sock, ctx->ctx_name,
547 (uint32_t) app_ctx_name_len);
548 if (ret < 0) {
549 goto error_io;
550 }
551
552 ret = recv_reply(app->sock, &reply, sizeof(reply));
553 if (ret < 0) {
554 goto error_io;
555 }
556
557 reply_ret_code = be32toh(reply.ret_code);
558 log_reply_code(reply_ret_code);
559 switch (reply_ret_code) {
560 case AGENT_RET_CODE_SUCCESS:
561 break;
562 default:
563 ret = LTTNG_ERR_UNK;
564 goto error;
565 }
566
567 return LTTNG_OK;
568
569 error_io:
570 ret = LTTNG_ERR_UST_ENABLE_FAIL;
571 error:
572 return ret;
573 }
574
575 /*
576 * Internal disable agent event call on a agent application. This function
577 * communicates with the agent to disable a given event.
578 *
579 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
580 */
581 static int disable_event(struct agent_app *app, struct agent_event *event)
582 {
583 int ret;
584 uint64_t data_size;
585 uint32_t reply_ret_code;
586 struct lttcomm_agent_disable_event msg;
587 struct lttcomm_agent_generic_reply reply;
588
589 assert(app);
590 assert(app->sock);
591 assert(event);
592
593 DBG2("Agent disabling event %s for app pid: %d and socket %d", event->name,
594 app->pid, app->sock->fd);
595
596 data_size = sizeof(msg);
597 memset(&msg, 0, sizeof(msg));
598 if (lttng_strncpy(msg.name, event->name, sizeof(msg.name))) {
599 ret = LTTNG_ERR_INVALID;
600 goto error;
601 }
602
603 ret = send_header(app->sock, data_size, AGENT_CMD_DISABLE, 0);
604 if (ret < 0) {
605 goto error_io;
606 }
607
608 ret = send_payload(app->sock, &msg, sizeof(msg));
609 if (ret < 0) {
610 goto error_io;
611 }
612
613 ret = recv_reply(app->sock, &reply, sizeof(reply));
614 if (ret < 0) {
615 goto error_io;
616 }
617
618 reply_ret_code = be32toh(reply.ret_code);
619 log_reply_code(reply_ret_code);
620 switch (reply_ret_code) {
621 case AGENT_RET_CODE_SUCCESS:
622 break;
623 case AGENT_RET_CODE_UNKNOWN_NAME:
624 ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
625 goto error;
626 default:
627 ret = LTTNG_ERR_UNK;
628 goto error;
629 }
630
631 return LTTNG_OK;
632
633 error_io:
634 ret = LTTNG_ERR_UST_DISABLE_FAIL;
635 error:
636 return ret;
637 }
638
639 /*
640 * Send back the registration DONE command to a given agent application.
641 *
642 * Return 0 on success or else a negative value.
643 */
644 int agent_send_registration_done(struct agent_app *app)
645 {
646 assert(app);
647 assert(app->sock);
648
649 DBG("Agent sending registration done to app socket %d", app->sock->fd);
650
651 return send_header(app->sock, 0, AGENT_CMD_REG_DONE, 0);
652 }
653
654 /*
655 * Enable agent event on every agent applications registered with the session
656 * daemon.
657 *
658 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
659 */
660 int agent_enable_event(struct agent_event *event,
661 enum lttng_domain_type domain)
662 {
663 int ret;
664 struct agent_app *app;
665 struct lttng_ht_iter iter;
666
667 assert(event);
668
669 rcu_read_lock();
670
671 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
672 node.node) {
673 if (app->domain != domain) {
674 continue;
675 }
676
677 /* Enable event on agent application through TCP socket. */
678 ret = enable_event(app, event);
679 if (ret != LTTNG_OK) {
680 goto error;
681 }
682 }
683
684 event->enabled = 1;
685 ret = LTTNG_OK;
686
687 error:
688 rcu_read_unlock();
689 return ret;
690 }
691
692 static
693 void destroy_app_ctx(struct agent_app_ctx *ctx)
694 {
695 free(ctx->provider_name);
696 free(ctx->ctx_name);
697 free(ctx);
698 }
699
700 static
701 struct agent_app_ctx *create_app_ctx(const struct lttng_event_context *ctx)
702 {
703 struct agent_app_ctx *agent_ctx = NULL;
704
705 if (!ctx) {
706 goto end;
707 }
708
709 assert(ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT);
710 agent_ctx = zmalloc(sizeof(*ctx));
711 if (!agent_ctx) {
712 goto end;
713 }
714
715 agent_ctx->provider_name = strdup(ctx->u.app_ctx.provider_name);
716 agent_ctx->ctx_name = strdup(ctx->u.app_ctx.ctx_name);
717 if (!agent_ctx->provider_name || !agent_ctx->ctx_name) {
718 destroy_app_ctx(agent_ctx);
719 agent_ctx = NULL;
720 }
721 end:
722 return agent_ctx;
723 }
724
725 /*
726 * Enable agent context on every agent applications registered with the session
727 * daemon.
728 *
729 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
730 */
731 int agent_enable_context(const struct lttng_event_context *ctx,
732 enum lttng_domain_type domain)
733 {
734 int ret;
735 struct agent_app *app;
736 struct lttng_ht_iter iter;
737
738 assert(ctx);
739 if (ctx->ctx != LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
740 ret = LTTNG_ERR_INVALID;
741 goto error;
742 }
743
744 rcu_read_lock();
745
746 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
747 node.node) {
748 struct agent_app_ctx *agent_ctx;
749
750 if (app->domain != domain) {
751 continue;
752 }
753
754 agent_ctx = create_app_ctx(ctx);
755 if (!agent_ctx) {
756 ret = LTTNG_ERR_NOMEM;
757 goto error_unlock;
758 }
759
760 /* Enable event on agent application through TCP socket. */
761 ret = app_context_op(app, agent_ctx, AGENT_CMD_APP_CTX_ENABLE);
762 destroy_app_ctx(agent_ctx);
763 if (ret != LTTNG_OK) {
764 goto error_unlock;
765 }
766 }
767
768 ret = LTTNG_OK;
769
770 error_unlock:
771 rcu_read_unlock();
772 error:
773 return ret;
774 }
775
776 /*
777 * Disable agent event on every agent application registered with the session
778 * daemon.
779 *
780 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
781 */
782 int agent_disable_event(struct agent_event *event,
783 enum lttng_domain_type domain)
784 {
785 int ret = LTTNG_OK;
786 struct agent_app *app;
787 struct lttng_ht_iter iter;
788
789 assert(event);
790 if (!event->enabled) {
791 goto end;
792 }
793
794 rcu_read_lock();
795
796 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
797 node.node) {
798 if (app->domain != domain) {
799 continue;
800 }
801
802 /* Enable event on agent application through TCP socket. */
803 ret = disable_event(app, event);
804 if (ret != LTTNG_OK) {
805 goto error;
806 }
807 }
808
809 event->enabled = 0;
810
811 error:
812 rcu_read_unlock();
813 end:
814 return ret;
815 }
816
817 /*
818 * Disable agent context on every agent application registered with the session
819 * daemon.
820 *
821 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
822 */
823 static int disable_context(struct agent_app_ctx *ctx,
824 enum lttng_domain_type domain)
825 {
826 int ret = LTTNG_OK;
827 struct agent_app *app;
828 struct lttng_ht_iter iter;
829
830 assert(ctx);
831
832 rcu_read_lock();
833 DBG2("Disabling agent application context %s:%s",
834 ctx->provider_name, ctx->ctx_name);
835 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
836 node.node) {
837 if (app->domain != domain) {
838 continue;
839 }
840
841 ret = app_context_op(app, ctx, AGENT_CMD_APP_CTX_DISABLE);
842 if (ret != LTTNG_OK) {
843 goto end;
844 }
845 }
846 end:
847 rcu_read_unlock();
848 return ret;
849 }
850
851 /*
852 * Ask every agent for the list of possible event. Events is allocated with the
853 * events of every agent application.
854 *
855 * Return the number of events or else a negative value.
856 */
857 int agent_list_events(struct lttng_event **events,
858 enum lttng_domain_type domain)
859 {
860 int ret;
861 size_t nbmem, count = 0;
862 struct agent_app *app;
863 struct lttng_event *tmp_events = NULL;
864 struct lttng_ht_iter iter;
865
866 assert(events);
867
868 DBG2("Agent listing events for domain %d", domain);
869
870 nbmem = UST_APP_EVENT_LIST_SIZE;
871 tmp_events = zmalloc(nbmem * sizeof(*tmp_events));
872 if (!tmp_events) {
873 PERROR("zmalloc agent list events");
874 ret = -ENOMEM;
875 goto error;
876 }
877
878 rcu_read_lock();
879 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
880 node.node) {
881 ssize_t nb_ev;
882 struct lttng_event *agent_events;
883
884 /* Skip domain not asked by the list. */
885 if (app->domain != domain) {
886 continue;
887 }
888
889 nb_ev = list_events(app, &agent_events);
890 if (nb_ev < 0) {
891 ret = nb_ev;
892 goto error_unlock;
893 }
894
895 if (count + nb_ev > nbmem) {
896 /* In case the realloc fails, we free the memory */
897 struct lttng_event *new_tmp_events;
898 size_t new_nbmem;
899
900 new_nbmem = max_t(size_t, count + nb_ev, nbmem << 1);
901 DBG2("Reallocating agent event list from %zu to %zu entries",
902 nbmem, new_nbmem);
903 new_tmp_events = realloc(tmp_events,
904 new_nbmem * sizeof(*new_tmp_events));
905 if (!new_tmp_events) {
906 PERROR("realloc agent events");
907 ret = -ENOMEM;
908 free(agent_events);
909 goto error_unlock;
910 }
911 /* Zero the new memory */
912 memset(new_tmp_events + nbmem, 0,
913 (new_nbmem - nbmem) * sizeof(*new_tmp_events));
914 nbmem = new_nbmem;
915 tmp_events = new_tmp_events;
916 }
917 memcpy(tmp_events + count, agent_events,
918 nb_ev * sizeof(*tmp_events));
919 free(agent_events);
920 count += nb_ev;
921 }
922 rcu_read_unlock();
923
924 ret = count;
925 *events = tmp_events;
926 return ret;
927
928 error_unlock:
929 rcu_read_unlock();
930 error:
931 free(tmp_events);
932 return ret;
933 }
934
935 /*
936 * Create a agent app object using the given PID.
937 *
938 * Return newly allocated object or else NULL on error.
939 */
940 struct agent_app *agent_create_app(pid_t pid, enum lttng_domain_type domain,
941 struct lttcomm_sock *sock)
942 {
943 struct agent_app *app;
944
945 assert(sock);
946
947 app = zmalloc(sizeof(*app));
948 if (!app) {
949 PERROR("zmalloc agent create");
950 goto error;
951 }
952
953 app->pid = pid;
954 app->domain = domain;
955 app->sock = sock;
956 lttng_ht_node_init_ulong(&app->node, (unsigned long) app->sock->fd);
957
958 error:
959 return app;
960 }
961
962 /*
963 * Lookup agent app by socket in the global hash table.
964 *
965 * RCU read side lock MUST be acquired.
966 *
967 * Return object if found else NULL.
968 */
969 struct agent_app *agent_find_app_by_sock(int sock)
970 {
971 struct lttng_ht_node_ulong *node;
972 struct lttng_ht_iter iter;
973 struct agent_app *app;
974
975 assert(sock >= 0);
976
977 lttng_ht_lookup(agent_apps_ht_by_sock, (void *)((unsigned long) sock), &iter);
978 node = lttng_ht_iter_get_node_ulong(&iter);
979 if (node == NULL) {
980 goto error;
981 }
982 app = caa_container_of(node, struct agent_app, node);
983
984 DBG3("Agent app pid %d found by sock %d.", app->pid, sock);
985 return app;
986
987 error:
988 DBG3("Agent app NOT found by sock %d.", sock);
989 return NULL;
990 }
991
992 /*
993 * Add agent application object to the global hash table.
994 */
995 void agent_add_app(struct agent_app *app)
996 {
997 assert(app);
998
999 DBG3("Agent adding app sock: %d and pid: %d to ht", app->sock->fd, app->pid);
1000 lttng_ht_add_unique_ulong(agent_apps_ht_by_sock, &app->node);
1001 }
1002
1003 /*
1004 * Delete agent application from the global hash table.
1005 *
1006 * rcu_read_lock() must be held by the caller.
1007 */
1008 void agent_delete_app(struct agent_app *app)
1009 {
1010 int ret;
1011 struct lttng_ht_iter iter;
1012
1013 assert(app);
1014
1015 DBG3("Agent deleting app pid: %d and sock: %d", app->pid, app->sock->fd);
1016
1017 iter.iter.node = &app->node.node;
1018 ret = lttng_ht_del(agent_apps_ht_by_sock, &iter);
1019 assert(!ret);
1020 }
1021
1022 /*
1023 * Destroy an agent application object by detaching it from its corresponding
1024 * UST app if one is connected by closing the socket. Finally, perform a
1025 * delayed memory reclaim.
1026 */
1027 void agent_destroy_app(struct agent_app *app)
1028 {
1029 assert(app);
1030
1031 if (app->sock) {
1032 app->sock->ops->close(app->sock);
1033 lttcomm_destroy_sock(app->sock);
1034 }
1035
1036 call_rcu(&app->node.head, destroy_app_agent_rcu);
1037 }
1038
1039 /*
1040 * Initialize an already allocated agent object.
1041 *
1042 * Return 0 on success or else a negative errno value.
1043 */
1044 int agent_init(struct agent *agt)
1045 {
1046 int ret;
1047
1048 assert(agt);
1049
1050 agt->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1051 if (!agt->events) {
1052 ret = -ENOMEM;
1053 goto error;
1054 }
1055 lttng_ht_node_init_u64(&agt->node, agt->domain);
1056
1057 CDS_INIT_LIST_HEAD(&agt->app_ctx_list);
1058 return 0;
1059
1060 error:
1061 return ret;
1062 }
1063
1064 /*
1065 * Add agent object to the given hash table.
1066 */
1067 void agent_add(struct agent *agt, struct lttng_ht *ht)
1068 {
1069 assert(agt);
1070 assert(ht);
1071
1072 DBG3("Agent adding from domain %d", agt->domain);
1073
1074 lttng_ht_add_unique_u64(ht, &agt->node);
1075 }
1076
1077 /*
1078 * Create an agent object for the given domain.
1079 *
1080 * Return the allocated agent or NULL on error.
1081 */
1082 struct agent *agent_create(enum lttng_domain_type domain)
1083 {
1084 int ret;
1085 struct agent *agt;
1086
1087 agt = zmalloc(sizeof(struct agent));
1088 if (!agt) {
1089 goto error;
1090 }
1091 agt->domain = domain;
1092
1093 ret = agent_init(agt);
1094 if (ret < 0) {
1095 free(agt);
1096 agt = NULL;
1097 goto error;
1098 }
1099
1100 error:
1101 return agt;
1102 }
1103
1104 /*
1105 * Create a newly allocated agent event data structure.
1106 * Ownership of filter_expression is taken.
1107 *
1108 * Return a new object else NULL on error.
1109 */
1110 struct agent_event *agent_create_event(const char *name,
1111 enum lttng_loglevel_type loglevel_type, int loglevel_value,
1112 struct lttng_filter_bytecode *filter, char *filter_expression)
1113 {
1114 struct agent_event *event = NULL;
1115
1116 DBG3("Agent create new event with name %s, loglevel type %d, \
1117 loglevel value %d and filter %s",
1118 name, loglevel_type, loglevel_value,
1119 filter_expression ? filter_expression : "NULL");
1120
1121 if (!name) {
1122 ERR("Failed to create agent event; no name provided.");
1123 goto error;
1124 }
1125
1126 event = zmalloc(sizeof(*event));
1127 if (!event) {
1128 goto error;
1129 }
1130
1131 strncpy(event->name, name, sizeof(event->name));
1132 event->name[sizeof(event->name) - 1] = '\0';
1133 lttng_ht_node_init_str(&event->node, event->name);
1134
1135 event->loglevel_value = loglevel_value;
1136 event->loglevel_type = loglevel_type;
1137 event->filter = filter;
1138 event->filter_expression = filter_expression;
1139 error:
1140 return event;
1141 }
1142
1143 /*
1144 * Unique add of a agent event to an agent object.
1145 */
1146 void agent_add_event(struct agent_event *event, struct agent *agt)
1147 {
1148 assert(event);
1149 assert(agt);
1150 assert(agt->events);
1151
1152 DBG3("Agent adding event %s", event->name);
1153 add_unique_agent_event(agt->events, event);
1154 agt->being_used = 1;
1155 }
1156
1157 /*
1158 * Unique add of a agent context to an agent object.
1159 */
1160 int agent_add_context(const struct lttng_event_context *ctx, struct agent *agt)
1161 {
1162 int ret = LTTNG_OK;
1163 struct agent_app_ctx *agent_ctx = NULL;
1164
1165 assert(ctx);
1166 assert(agt);
1167 assert(agt->events);
1168 assert(ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT);
1169
1170 agent_ctx = create_app_ctx(ctx);
1171 if (!agent_ctx) {
1172 ret = LTTNG_ERR_NOMEM;
1173 goto end;
1174 }
1175
1176 DBG3("Agent adding context %s:%s", ctx->u.app_ctx.provider_name,
1177 ctx->u.app_ctx.ctx_name);
1178 cds_list_add_tail_rcu(&agent_ctx->list_node, &agt->app_ctx_list);
1179 end:
1180 return ret;
1181 }
1182
1183 /*
1184 * Find multiple agent events sharing the given name.
1185 *
1186 * RCU read side lock MUST be acquired. It must be held for the
1187 * duration of the iteration.
1188 *
1189 * Sets the given iterator.
1190 */
1191 void agent_find_events_by_name(const char *name, struct agent *agt,
1192 struct lttng_ht_iter* iter)
1193 {
1194 struct lttng_ht *ht;
1195 struct agent_ht_key key;
1196
1197 assert(name);
1198 assert(agt);
1199 assert(agt->events);
1200 assert(iter);
1201
1202 ht = agt->events;
1203 key.name = name;
1204
1205 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1206 ht_match_event_by_name, &key, &iter->iter);
1207 }
1208
1209 /*
1210 * Get the next agent event duplicate by name. This should be called
1211 * after a call to agent_find_events_by_name() to iterate on events.
1212 *
1213 * The RCU read lock must be held during the iteration and for as long
1214 * as the object the iterator points to remains in use.
1215 */
1216 void agent_event_next_duplicate(const char *name,
1217 struct agent *agt, struct lttng_ht_iter* iter)
1218 {
1219 struct agent_ht_key key;
1220
1221 key.name = name;
1222
1223 cds_lfht_next_duplicate(agt->events->ht, ht_match_event_by_name,
1224 &key, &iter->iter);
1225 }
1226
1227 /*
1228 * Find a agent event in the given agent using name, loglevel and filter.
1229 *
1230 * RCU read side lock MUST be acquired. It must be kept for as long as
1231 * the returned agent_event is used.
1232 *
1233 * Return object if found else NULL.
1234 */
1235 struct agent_event *agent_find_event(const char *name,
1236 enum lttng_loglevel_type loglevel_type, int loglevel_value,
1237 char *filter_expression, struct agent *agt)
1238 {
1239 struct lttng_ht_node_str *node;
1240 struct lttng_ht_iter iter;
1241 struct lttng_ht *ht;
1242 struct agent_ht_key key;
1243
1244 assert(name);
1245 assert(agt);
1246 assert(agt->events);
1247
1248 ht = agt->events;
1249 key.name = name;
1250 key.loglevel_value = loglevel_value;
1251 key.loglevel_type = loglevel_type;
1252 key.filter_expression = filter_expression;
1253
1254 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1255 ht_match_event, &key, &iter.iter);
1256 node = lttng_ht_iter_get_node_str(&iter);
1257 if (node == NULL) {
1258 goto error;
1259 }
1260
1261 DBG3("Agent event found %s.", name);
1262 return caa_container_of(node, struct agent_event, node);
1263
1264 error:
1265 DBG3("Agent event NOT found %s.", name);
1266 return NULL;
1267 }
1268
1269 /*
1270 * Free given agent event. This event must not be globally visible at this
1271 * point (only expected to be used on failure just after event creation). After
1272 * this call, the pointer is not usable anymore.
1273 */
1274 void agent_destroy_event(struct agent_event *event)
1275 {
1276 assert(event);
1277
1278 free(event->filter);
1279 free(event->filter_expression);
1280 free(event->exclusion);
1281 free(event);
1282 }
1283
1284 static
1285 void destroy_app_ctx_rcu(struct rcu_head *head)
1286 {
1287 struct agent_app_ctx *ctx =
1288 caa_container_of(head, struct agent_app_ctx, rcu_node);
1289
1290 destroy_app_ctx(ctx);
1291 }
1292
1293 /*
1294 * Destroy an agent completely.
1295 */
1296 void agent_destroy(struct agent *agt)
1297 {
1298 struct lttng_ht_node_str *node;
1299 struct lttng_ht_iter iter;
1300 struct agent_app_ctx *ctx;
1301
1302 assert(agt);
1303
1304 DBG3("Agent destroy");
1305
1306 rcu_read_lock();
1307 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, node, node) {
1308 int ret;
1309 struct agent_event *event;
1310
1311 /*
1312 * When destroying an event, we have to try to disable it on the
1313 * agent side so the event stops generating data. The return
1314 * value is not important since we have to continue anyway
1315 * destroying the object.
1316 */
1317 event = caa_container_of(node, struct agent_event, node);
1318 (void) agent_disable_event(event, agt->domain);
1319
1320 ret = lttng_ht_del(agt->events, &iter);
1321 assert(!ret);
1322 call_rcu(&node->head, destroy_event_agent_rcu);
1323 }
1324
1325 cds_list_for_each_entry_rcu(ctx, &agt->app_ctx_list, list_node) {
1326 (void) disable_context(ctx, agt->domain);
1327 cds_list_del(&ctx->list_node);
1328 call_rcu(&ctx->rcu_node, destroy_app_ctx_rcu);
1329 }
1330 rcu_read_unlock();
1331 ht_cleanup_push(agt->events);
1332 free(agt);
1333 }
1334
1335 /*
1336 * Allocate agent_apps_ht_by_sock.
1337 */
1338 int agent_app_ht_alloc(void)
1339 {
1340 int ret = 0;
1341
1342 agent_apps_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1343 if (!agent_apps_ht_by_sock) {
1344 ret = -1;
1345 }
1346
1347 return ret;
1348 }
1349
1350 /*
1351 * Destroy a agent application by socket.
1352 */
1353 void agent_destroy_app_by_sock(int sock)
1354 {
1355 struct agent_app *app;
1356
1357 assert(sock >= 0);
1358
1359 /*
1360 * Not finding an application is a very important error that should NEVER
1361 * happen. The hash table deletion is ONLY done through this call when the
1362 * main sessiond thread is torn down.
1363 */
1364 rcu_read_lock();
1365 app = agent_find_app_by_sock(sock);
1366 assert(app);
1367
1368 /* RCU read side lock is assumed to be held by this function. */
1369 agent_delete_app(app);
1370
1371 /* The application is freed in a RCU call but the socket is closed here. */
1372 agent_destroy_app(app);
1373 rcu_read_unlock();
1374 }
1375
1376 /*
1377 * Clean-up the agent app hash table and destroy it.
1378 */
1379 void agent_app_ht_clean(void)
1380 {
1381 struct lttng_ht_node_ulong *node;
1382 struct lttng_ht_iter iter;
1383
1384 if (!agent_apps_ht_by_sock) {
1385 return;
1386 }
1387 rcu_read_lock();
1388 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, node, node) {
1389 struct agent_app *app;
1390
1391 app = caa_container_of(node, struct agent_app, node);
1392 agent_destroy_app_by_sock(app->sock->fd);
1393 }
1394 rcu_read_unlock();
1395
1396 lttng_ht_destroy(agent_apps_ht_by_sock);
1397 }
1398
1399 /*
1400 * Update a agent application (given socket) using the given agent.
1401 *
1402 * Note that this function is most likely to be used with a tracing session
1403 * thus the caller should make sure to hold the appropriate lock(s).
1404 */
1405 void agent_update(struct agent *agt, int sock)
1406 {
1407 int ret;
1408 struct agent_app *app;
1409 struct agent_event *event;
1410 struct lttng_ht_iter iter;
1411 struct agent_app_ctx *ctx;
1412
1413 assert(agt);
1414 assert(sock >= 0);
1415
1416 DBG("Agent updating app socket %d", sock);
1417
1418 rcu_read_lock();
1419 app = agent_find_app_by_sock(sock);
1420 /*
1421 * We are in the registration path thus if the application is gone,
1422 * there is a serious code flow error.
1423 */
1424 assert(app);
1425 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
1426 /* Skip event if disabled. */
1427 if (!event->enabled) {
1428 continue;
1429 }
1430
1431 ret = enable_event(app, event);
1432 if (ret != LTTNG_OK) {
1433 DBG2("Agent update unable to enable event %s on app pid: %d sock %d",
1434 event->name, app->pid, app->sock->fd);
1435 /* Let's try the others here and don't assume the app is dead. */
1436 continue;
1437 }
1438 }
1439
1440 cds_list_for_each_entry_rcu(ctx, &agt->app_ctx_list, list_node) {
1441 ret = app_context_op(app, ctx, AGENT_CMD_APP_CTX_ENABLE);
1442 if (ret != LTTNG_OK) {
1443 DBG2("Agent update unable to add application context %s:%s on app pid: %d sock %d",
1444 ctx->provider_name, ctx->ctx_name,
1445 app->pid, app->sock->fd);
1446 continue;
1447 }
1448 }
1449
1450 rcu_read_unlock();
1451 }
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