Fix: illegal memory access in enable_event
[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 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
598 ret = send_header(app->sock, data_size, AGENT_CMD_DISABLE, 0);
599 if (ret < 0) {
600 goto error_io;
601 }
602
603 memset(&msg, 0, sizeof(msg));
604 strncpy(msg.name, event->name, sizeof(msg.name));
605 ret = send_payload(app->sock, &msg, sizeof(msg));
606 if (ret < 0) {
607 goto error_io;
608 }
609
610 ret = recv_reply(app->sock, &reply, sizeof(reply));
611 if (ret < 0) {
612 goto error_io;
613 }
614
615 reply_ret_code = be32toh(reply.ret_code);
616 log_reply_code(reply_ret_code);
617 switch (reply_ret_code) {
618 case AGENT_RET_CODE_SUCCESS:
619 break;
620 case AGENT_RET_CODE_UNKNOWN_NAME:
621 ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
622 goto error;
623 default:
624 ret = LTTNG_ERR_UNK;
625 goto error;
626 }
627
628 return LTTNG_OK;
629
630 error_io:
631 ret = LTTNG_ERR_UST_DISABLE_FAIL;
632 error:
633 return ret;
634 }
635
636 /*
637 * Send back the registration DONE command to a given agent application.
638 *
639 * Return 0 on success or else a negative value.
640 */
641 int agent_send_registration_done(struct agent_app *app)
642 {
643 assert(app);
644 assert(app->sock);
645
646 DBG("Agent sending registration done to app socket %d", app->sock->fd);
647
648 return send_header(app->sock, 0, AGENT_CMD_REG_DONE, 0);
649 }
650
651 /*
652 * Enable agent event on every agent applications registered with the session
653 * daemon.
654 *
655 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
656 */
657 int agent_enable_event(struct agent_event *event,
658 enum lttng_domain_type domain)
659 {
660 int ret;
661 struct agent_app *app;
662 struct lttng_ht_iter iter;
663
664 assert(event);
665
666 rcu_read_lock();
667
668 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
669 node.node) {
670 if (app->domain != domain) {
671 continue;
672 }
673
674 /* Enable event on agent application through TCP socket. */
675 ret = enable_event(app, event);
676 if (ret != LTTNG_OK) {
677 goto error;
678 }
679 }
680
681 event->enabled = 1;
682 ret = LTTNG_OK;
683
684 error:
685 rcu_read_unlock();
686 return ret;
687 }
688
689 static
690 void destroy_app_ctx(struct agent_app_ctx *ctx)
691 {
692 free(ctx->provider_name);
693 free(ctx->ctx_name);
694 free(ctx);
695 }
696
697 static
698 struct agent_app_ctx *create_app_ctx(struct lttng_event_context *ctx)
699 {
700 struct agent_app_ctx *agent_ctx = NULL;
701
702 if (!ctx) {
703 goto end;
704 }
705
706 assert(ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT);
707 agent_ctx = zmalloc(sizeof(*ctx));
708 if (!agent_ctx) {
709 goto end;
710 }
711
712 agent_ctx->provider_name = strdup(ctx->u.app_ctx.provider_name);
713 agent_ctx->ctx_name = strdup(ctx->u.app_ctx.ctx_name);
714 if (!agent_ctx->provider_name || !agent_ctx->ctx_name) {
715 destroy_app_ctx(agent_ctx);
716 agent_ctx = NULL;
717 }
718 end:
719 return agent_ctx;
720 }
721
722 /*
723 * Enable agent context on every agent applications registered with the session
724 * daemon.
725 *
726 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
727 */
728 int agent_enable_context(struct lttng_event_context *ctx,
729 enum lttng_domain_type domain)
730 {
731 int ret;
732 struct agent_app *app;
733 struct lttng_ht_iter iter;
734
735 assert(ctx);
736 if (ctx->ctx != LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
737 ret = LTTNG_ERR_INVALID;
738 goto error;
739 }
740
741 rcu_read_lock();
742
743 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
744 node.node) {
745 struct agent_app_ctx *agent_ctx;
746
747 if (app->domain != domain) {
748 continue;
749 }
750
751 agent_ctx = create_app_ctx(ctx);
752 if (!agent_ctx) {
753 ret = LTTNG_ERR_NOMEM;
754 goto error_unlock;
755 }
756
757 /* Enable event on agent application through TCP socket. */
758 ret = app_context_op(app, agent_ctx, AGENT_CMD_APP_CTX_ENABLE);
759 destroy_app_ctx(agent_ctx);
760 if (ret != LTTNG_OK) {
761 goto error_unlock;
762 }
763 }
764
765 ret = LTTNG_OK;
766
767 error_unlock:
768 rcu_read_unlock();
769 error:
770 return ret;
771 }
772
773 /*
774 * Disable agent event on every agent application registered with the session
775 * daemon.
776 *
777 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
778 */
779 int agent_disable_event(struct agent_event *event,
780 enum lttng_domain_type domain)
781 {
782 int ret = LTTNG_OK;
783 struct agent_app *app;
784 struct lttng_ht_iter iter;
785
786 assert(event);
787 if (!event->enabled) {
788 goto end;
789 }
790
791 rcu_read_lock();
792
793 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
794 node.node) {
795 if (app->domain != domain) {
796 continue;
797 }
798
799 /* Enable event on agent application through TCP socket. */
800 ret = disable_event(app, event);
801 if (ret != LTTNG_OK) {
802 goto error;
803 }
804 }
805
806 event->enabled = 0;
807
808 error:
809 rcu_read_unlock();
810 end:
811 return ret;
812 }
813
814 /*
815 * Disable agent context on every agent application registered with the session
816 * daemon.
817 *
818 * Return LTTNG_OK on success or else a LTTNG_ERR* code.
819 */
820 int disable_context(struct agent_app_ctx *ctx, enum lttng_domain_type domain)
821 {
822 int ret = LTTNG_OK;
823 struct agent_app *app;
824 struct lttng_ht_iter iter;
825
826 assert(ctx);
827
828 rcu_read_lock();
829 DBG2("Disabling agent application context %s:%s",
830 ctx->provider_name, ctx->ctx_name);
831 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
832 node.node) {
833 if (app->domain != domain) {
834 continue;
835 }
836
837 ret = app_context_op(app, ctx, AGENT_CMD_APP_CTX_DISABLE);
838 if (ret != LTTNG_OK) {
839 goto end;
840 }
841 }
842 end:
843 rcu_read_unlock();
844 return ret;
845 }
846
847 /*
848 * Ask every agent for the list of possible event. Events is allocated with the
849 * events of every agent application.
850 *
851 * Return the number of events or else a negative value.
852 */
853 int agent_list_events(struct lttng_event **events,
854 enum lttng_domain_type domain)
855 {
856 int ret;
857 size_t nbmem, count = 0;
858 struct agent_app *app;
859 struct lttng_event *tmp_events = NULL;
860 struct lttng_ht_iter iter;
861
862 assert(events);
863
864 DBG2("Agent listing events for domain %d", domain);
865
866 nbmem = UST_APP_EVENT_LIST_SIZE;
867 tmp_events = zmalloc(nbmem * sizeof(*tmp_events));
868 if (!tmp_events) {
869 PERROR("zmalloc agent list events");
870 ret = -ENOMEM;
871 goto error;
872 }
873
874 rcu_read_lock();
875 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, app,
876 node.node) {
877 ssize_t nb_ev;
878 struct lttng_event *agent_events;
879
880 /* Skip domain not asked by the list. */
881 if (app->domain != domain) {
882 continue;
883 }
884
885 nb_ev = list_events(app, &agent_events);
886 if (nb_ev < 0) {
887 ret = nb_ev;
888 goto error_unlock;
889 }
890
891 if (count + nb_ev > nbmem) {
892 /* In case the realloc fails, we free the memory */
893 struct lttng_event *new_tmp_events;
894 size_t new_nbmem;
895
896 new_nbmem = max_t(size_t, count + nb_ev, nbmem << 1);
897 DBG2("Reallocating agent event list from %zu to %zu entries",
898 nbmem, new_nbmem);
899 new_tmp_events = realloc(tmp_events,
900 new_nbmem * sizeof(*new_tmp_events));
901 if (!new_tmp_events) {
902 PERROR("realloc agent events");
903 ret = -ENOMEM;
904 free(agent_events);
905 goto error_unlock;
906 }
907 /* Zero the new memory */
908 memset(new_tmp_events + nbmem, 0,
909 (new_nbmem - nbmem) * sizeof(*new_tmp_events));
910 nbmem = new_nbmem;
911 tmp_events = new_tmp_events;
912 }
913 memcpy(tmp_events + count, agent_events,
914 nb_ev * sizeof(*tmp_events));
915 free(agent_events);
916 count += nb_ev;
917 }
918 rcu_read_unlock();
919
920 ret = count;
921 *events = tmp_events;
922 return ret;
923
924 error_unlock:
925 rcu_read_unlock();
926 error:
927 free(tmp_events);
928 return ret;
929 }
930
931 /*
932 * Create a agent app object using the given PID.
933 *
934 * Return newly allocated object or else NULL on error.
935 */
936 struct agent_app *agent_create_app(pid_t pid, enum lttng_domain_type domain,
937 struct lttcomm_sock *sock)
938 {
939 struct agent_app *app;
940
941 assert(sock);
942
943 app = zmalloc(sizeof(*app));
944 if (!app) {
945 PERROR("zmalloc agent create");
946 goto error;
947 }
948
949 app->pid = pid;
950 app->domain = domain;
951 app->sock = sock;
952 lttng_ht_node_init_ulong(&app->node, (unsigned long) app->sock->fd);
953
954 error:
955 return app;
956 }
957
958 /*
959 * Lookup agent app by socket in the global hash table.
960 *
961 * RCU read side lock MUST be acquired.
962 *
963 * Return object if found else NULL.
964 */
965 struct agent_app *agent_find_app_by_sock(int sock)
966 {
967 struct lttng_ht_node_ulong *node;
968 struct lttng_ht_iter iter;
969 struct agent_app *app;
970
971 assert(sock >= 0);
972
973 lttng_ht_lookup(agent_apps_ht_by_sock, (void *)((unsigned long) sock), &iter);
974 node = lttng_ht_iter_get_node_ulong(&iter);
975 if (node == NULL) {
976 goto error;
977 }
978 app = caa_container_of(node, struct agent_app, node);
979
980 DBG3("Agent app pid %d found by sock %d.", app->pid, sock);
981 return app;
982
983 error:
984 DBG3("Agent app NOT found by sock %d.", sock);
985 return NULL;
986 }
987
988 /*
989 * Add agent application object to the global hash table.
990 */
991 void agent_add_app(struct agent_app *app)
992 {
993 assert(app);
994
995 DBG3("Agent adding app sock: %d and pid: %d to ht", app->sock->fd, app->pid);
996 lttng_ht_add_unique_ulong(agent_apps_ht_by_sock, &app->node);
997 }
998
999 /*
1000 * Delete agent application from the global hash table.
1001 *
1002 * rcu_read_lock() must be held by the caller.
1003 */
1004 void agent_delete_app(struct agent_app *app)
1005 {
1006 int ret;
1007 struct lttng_ht_iter iter;
1008
1009 assert(app);
1010
1011 DBG3("Agent deleting app pid: %d and sock: %d", app->pid, app->sock->fd);
1012
1013 iter.iter.node = &app->node.node;
1014 ret = lttng_ht_del(agent_apps_ht_by_sock, &iter);
1015 assert(!ret);
1016 }
1017
1018 /*
1019 * Destroy an agent application object by detaching it from its corresponding
1020 * UST app if one is connected by closing the socket. Finally, perform a
1021 * delayed memory reclaim.
1022 */
1023 void agent_destroy_app(struct agent_app *app)
1024 {
1025 assert(app);
1026
1027 if (app->sock) {
1028 app->sock->ops->close(app->sock);
1029 lttcomm_destroy_sock(app->sock);
1030 }
1031
1032 call_rcu(&app->node.head, destroy_app_agent_rcu);
1033 }
1034
1035 /*
1036 * Initialize an already allocated agent object.
1037 *
1038 * Return 0 on success or else a negative errno value.
1039 */
1040 int agent_init(struct agent *agt)
1041 {
1042 int ret;
1043
1044 assert(agt);
1045
1046 agt->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
1047 if (!agt->events) {
1048 ret = -ENOMEM;
1049 goto error;
1050 }
1051 lttng_ht_node_init_u64(&agt->node, agt->domain);
1052
1053 CDS_INIT_LIST_HEAD(&agt->app_ctx_list);
1054 return 0;
1055
1056 error:
1057 return ret;
1058 }
1059
1060 /*
1061 * Add agent object to the given hash table.
1062 */
1063 void agent_add(struct agent *agt, struct lttng_ht *ht)
1064 {
1065 assert(agt);
1066 assert(ht);
1067
1068 DBG3("Agent adding from domain %d", agt->domain);
1069
1070 lttng_ht_add_unique_u64(ht, &agt->node);
1071 }
1072
1073 /*
1074 * Create an agent object for the given domain.
1075 *
1076 * Return the allocated agent or NULL on error.
1077 */
1078 struct agent *agent_create(enum lttng_domain_type domain)
1079 {
1080 int ret;
1081 struct agent *agt;
1082
1083 agt = zmalloc(sizeof(struct agent));
1084 if (!agt) {
1085 goto error;
1086 }
1087 agt->domain = domain;
1088
1089 ret = agent_init(agt);
1090 if (ret < 0) {
1091 free(agt);
1092 agt = NULL;
1093 goto error;
1094 }
1095
1096 error:
1097 return agt;
1098 }
1099
1100 /*
1101 * Create a newly allocated agent event data structure.
1102 * Ownership of filter_expression is taken.
1103 *
1104 * Return a new object else NULL on error.
1105 */
1106 struct agent_event *agent_create_event(const char *name,
1107 enum lttng_loglevel_type loglevel_type, int loglevel_value,
1108 struct lttng_filter_bytecode *filter, char *filter_expression)
1109 {
1110 struct agent_event *event = NULL;
1111
1112 DBG3("Agent create new event with name %s, loglevel type %d, \
1113 loglevel value %d and filter %s",
1114 name, loglevel_type, loglevel_value,
1115 filter_expression ? filter_expression : "NULL");
1116
1117 if (!name) {
1118 ERR("Failed to create agent event; no name provided.");
1119 goto error;
1120 }
1121
1122 event = zmalloc(sizeof(*event));
1123 if (!event) {
1124 goto error;
1125 }
1126
1127 strncpy(event->name, name, sizeof(event->name));
1128 event->name[sizeof(event->name) - 1] = '\0';
1129 lttng_ht_node_init_str(&event->node, event->name);
1130
1131 event->loglevel_value = loglevel_value;
1132 event->loglevel_type = loglevel_type;
1133 event->filter = filter;
1134 event->filter_expression = filter_expression;
1135 error:
1136 return event;
1137 }
1138
1139 /*
1140 * Unique add of a agent event to an agent object.
1141 */
1142 void agent_add_event(struct agent_event *event, struct agent *agt)
1143 {
1144 assert(event);
1145 assert(agt);
1146 assert(agt->events);
1147
1148 DBG3("Agent adding event %s", event->name);
1149 add_unique_agent_event(agt->events, event);
1150 agt->being_used = 1;
1151 }
1152
1153 /*
1154 * Unique add of a agent context to an agent object.
1155 */
1156 int agent_add_context(struct lttng_event_context *ctx, struct agent *agt)
1157 {
1158 int ret = LTTNG_OK;
1159 struct agent_app_ctx *agent_ctx = NULL;
1160
1161 assert(ctx);
1162 assert(agt);
1163 assert(agt->events);
1164 assert(ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT);
1165
1166 agent_ctx = create_app_ctx(ctx);
1167 if (!agent_ctx) {
1168 ret = LTTNG_ERR_NOMEM;
1169 goto end;
1170 }
1171
1172 DBG3("Agent adding context %s:%s", ctx->u.app_ctx.provider_name,
1173 ctx->u.app_ctx.ctx_name);
1174 cds_list_add_tail_rcu(&agent_ctx->list_node, &agt->app_ctx_list);
1175 end:
1176 return ret;
1177 }
1178
1179 /*
1180 * Find multiple agent events sharing the given name.
1181 *
1182 * RCU read side lock MUST be acquired. It must be held for the
1183 * duration of the iteration.
1184 *
1185 * Sets the given iterator.
1186 */
1187 void agent_find_events_by_name(const char *name, struct agent *agt,
1188 struct lttng_ht_iter* iter)
1189 {
1190 struct lttng_ht *ht;
1191 struct agent_ht_key key;
1192
1193 assert(name);
1194 assert(agt);
1195 assert(agt->events);
1196 assert(iter);
1197
1198 ht = agt->events;
1199 key.name = name;
1200
1201 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1202 ht_match_event_by_name, &key, &iter->iter);
1203 }
1204
1205 /*
1206 * Get the next agent event duplicate by name. This should be called
1207 * after a call to agent_find_events_by_name() to iterate on events.
1208 *
1209 * The RCU read lock must be held during the iteration and for as long
1210 * as the object the iterator points to remains in use.
1211 */
1212 void agent_event_next_duplicate(const char *name,
1213 struct agent *agt, struct lttng_ht_iter* iter)
1214 {
1215 struct agent_ht_key key;
1216
1217 key.name = name;
1218
1219 cds_lfht_next_duplicate(agt->events->ht, ht_match_event_by_name,
1220 &key, &iter->iter);
1221 }
1222
1223 /*
1224 * Find a agent event in the given agent using name, loglevel and filter.
1225 *
1226 * RCU read side lock MUST be acquired. It must be kept for as long as
1227 * the returned agent_event is used.
1228 *
1229 * Return object if found else NULL.
1230 */
1231 struct agent_event *agent_find_event(const char *name,
1232 enum lttng_loglevel_type loglevel_type, int loglevel_value,
1233 char *filter_expression, struct agent *agt)
1234 {
1235 struct lttng_ht_node_str *node;
1236 struct lttng_ht_iter iter;
1237 struct lttng_ht *ht;
1238 struct agent_ht_key key;
1239
1240 assert(name);
1241 assert(agt);
1242 assert(agt->events);
1243
1244 ht = agt->events;
1245 key.name = name;
1246 key.loglevel_value = loglevel_value;
1247 key.loglevel_type = loglevel_type;
1248 key.filter_expression = filter_expression;
1249
1250 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
1251 ht_match_event, &key, &iter.iter);
1252 node = lttng_ht_iter_get_node_str(&iter);
1253 if (node == NULL) {
1254 goto error;
1255 }
1256
1257 DBG3("Agent event found %s.", name);
1258 return caa_container_of(node, struct agent_event, node);
1259
1260 error:
1261 DBG3("Agent event NOT found %s.", name);
1262 return NULL;
1263 }
1264
1265 /*
1266 * Free given agent event. This event must not be globally visible at this
1267 * point (only expected to be used on failure just after event creation). After
1268 * this call, the pointer is not usable anymore.
1269 */
1270 void agent_destroy_event(struct agent_event *event)
1271 {
1272 assert(event);
1273
1274 free(event->filter);
1275 free(event->filter_expression);
1276 free(event->exclusion);
1277 free(event);
1278 }
1279
1280 static
1281 void destroy_app_ctx_rcu(struct rcu_head *head)
1282 {
1283 struct agent_app_ctx *ctx =
1284 caa_container_of(head, struct agent_app_ctx, rcu_node);
1285
1286 destroy_app_ctx(ctx);
1287 }
1288
1289 /*
1290 * Destroy an agent completely.
1291 */
1292 void agent_destroy(struct agent *agt)
1293 {
1294 struct lttng_ht_node_str *node;
1295 struct lttng_ht_iter iter;
1296 struct agent_app_ctx *ctx;
1297
1298 assert(agt);
1299
1300 DBG3("Agent destroy");
1301
1302 rcu_read_lock();
1303 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, node, node) {
1304 int ret;
1305 struct agent_event *event;
1306
1307 /*
1308 * When destroying an event, we have to try to disable it on the
1309 * agent side so the event stops generating data. The return
1310 * value is not important since we have to continue anyway
1311 * destroying the object.
1312 */
1313 event = caa_container_of(node, struct agent_event, node);
1314 (void) agent_disable_event(event, agt->domain);
1315
1316 ret = lttng_ht_del(agt->events, &iter);
1317 assert(!ret);
1318 call_rcu(&node->head, destroy_event_agent_rcu);
1319 }
1320
1321 cds_list_for_each_entry_rcu(ctx, &agt->app_ctx_list, list_node) {
1322 (void) disable_context(ctx, agt->domain);
1323 cds_list_del(&ctx->list_node);
1324 call_rcu(&ctx->rcu_node, destroy_app_ctx_rcu);
1325 }
1326 rcu_read_unlock();
1327 ht_cleanup_push(agt->events);
1328 free(agt);
1329 }
1330
1331 /*
1332 * Allocate agent_apps_ht_by_sock.
1333 */
1334 int agent_app_ht_alloc(void)
1335 {
1336 int ret = 0;
1337
1338 agent_apps_ht_by_sock = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
1339 if (!agent_apps_ht_by_sock) {
1340 ret = -1;
1341 }
1342
1343 return ret;
1344 }
1345
1346 /*
1347 * Destroy a agent application by socket.
1348 */
1349 void agent_destroy_app_by_sock(int sock)
1350 {
1351 struct agent_app *app;
1352
1353 assert(sock >= 0);
1354
1355 /*
1356 * Not finding an application is a very important error that should NEVER
1357 * happen. The hash table deletion is ONLY done through this call when the
1358 * main sessiond thread is torn down.
1359 */
1360 rcu_read_lock();
1361 app = agent_find_app_by_sock(sock);
1362 assert(app);
1363
1364 /* RCU read side lock is assumed to be held by this function. */
1365 agent_delete_app(app);
1366
1367 /* The application is freed in a RCU call but the socket is closed here. */
1368 agent_destroy_app(app);
1369 rcu_read_unlock();
1370 }
1371
1372 /*
1373 * Clean-up the agent app hash table and destroy it.
1374 */
1375 void agent_app_ht_clean(void)
1376 {
1377 struct lttng_ht_node_ulong *node;
1378 struct lttng_ht_iter iter;
1379
1380 if (!agent_apps_ht_by_sock) {
1381 return;
1382 }
1383 rcu_read_lock();
1384 cds_lfht_for_each_entry(agent_apps_ht_by_sock->ht, &iter.iter, node, node) {
1385 struct agent_app *app;
1386
1387 app = caa_container_of(node, struct agent_app, node);
1388 agent_destroy_app_by_sock(app->sock->fd);
1389 }
1390 rcu_read_unlock();
1391
1392 lttng_ht_destroy(agent_apps_ht_by_sock);
1393 }
1394
1395 /*
1396 * Update a agent application (given socket) using the given agent.
1397 *
1398 * Note that this function is most likely to be used with a tracing session
1399 * thus the caller should make sure to hold the appropriate lock(s).
1400 */
1401 void agent_update(struct agent *agt, int sock)
1402 {
1403 int ret;
1404 struct agent_app *app;
1405 struct agent_event *event;
1406 struct lttng_ht_iter iter;
1407 struct agent_app_ctx *ctx;
1408
1409 assert(agt);
1410 assert(sock >= 0);
1411
1412 DBG("Agent updating app socket %d", sock);
1413
1414 rcu_read_lock();
1415 app = agent_find_app_by_sock(sock);
1416 /*
1417 * We are in the registration path thus if the application is gone,
1418 * there is a serious code flow error.
1419 */
1420 assert(app);
1421 cds_lfht_for_each_entry(agt->events->ht, &iter.iter, event, node.node) {
1422 /* Skip event if disabled. */
1423 if (!event->enabled) {
1424 continue;
1425 }
1426
1427 ret = enable_event(app, event);
1428 if (ret != LTTNG_OK) {
1429 DBG2("Agent update unable to enable event %s on app pid: %d sock %d",
1430 event->name, app->pid, app->sock->fd);
1431 /* Let's try the others here and don't assume the app is dead. */
1432 continue;
1433 }
1434 }
1435
1436 cds_list_for_each_entry_rcu(ctx, &agt->app_ctx_list, list_node) {
1437 ret = app_context_op(app, ctx, AGENT_CMD_APP_CTX_ENABLE);
1438 if (ret != LTTNG_OK) {
1439 DBG2("Agent update unable to add application context %s:%s on app pid: %d sock %d",
1440 ctx->provider_name, ctx->ctx_name,
1441 app->pid, app->sock->fd);
1442 continue;
1443 }
1444 }
1445
1446 rcu_read_unlock();
1447 }
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