9f9afa25acd1f45d64eb7cd6e7ce5b0b53b571c2
[lttng-tools.git] / src / bin / lttng-sessiond / client.c
1 /*
2 * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
3 * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 * Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@efficios.com>
5 *
6 * SPDX-License-Identifier: GPL-2.0-only
7 *
8 */
9
10 #include "common/buffer-view.h"
11 #include "common/dynamic-buffer.h"
12 #include "common/sessiond-comm/sessiond-comm.h"
13 #include "lttng/lttng-error.h"
14 #include "lttng/tracker.h"
15 #include <common/compat/getenv.h>
16 #include <common/tracker.h>
17 #include <common/unix.h>
18 #include <common/utils.h>
19 #include <lttng/event-internal.h>
20 #include <lttng/session-descriptor-internal.h>
21 #include <lttng/session-internal.h>
22 #include <lttng/userspace-probe-internal.h>
23 #include <pthread.h>
24 #include <signal.h>
25 #include <stddef.h>
26 #include <sys/stat.h>
27
28 #include "client.h"
29 #include "lttng-sessiond.h"
30 #include "cmd.h"
31 #include "kernel.h"
32 #include "save.h"
33 #include "health-sessiond.h"
34 #include "testpoint.h"
35 #include "utils.h"
36 #include "manage-consumer.h"
37 #include "clear.h"
38
39 static bool is_root;
40
41 static struct thread_state {
42 sem_t ready;
43 bool running;
44 int client_sock;
45 } thread_state;
46
47 static void set_thread_status(bool running)
48 {
49 DBG("Marking client thread's state as %s", running ? "running" : "error");
50 thread_state.running = running;
51 sem_post(&thread_state.ready);
52 }
53
54 static bool wait_thread_status(void)
55 {
56 DBG("Waiting for client thread to be ready");
57 sem_wait(&thread_state.ready);
58 if (thread_state.running) {
59 DBG("Client thread is ready");
60 } else {
61 ERR("Initialization of client thread failed");
62 }
63
64 return thread_state.running;
65 }
66
67 /*
68 * Setup the outgoing data buffer for the response (llm) by allocating the
69 * right amount of memory and copying the original information from the lsm
70 * structure.
71 *
72 * Return 0 on success, negative value on error.
73 */
74 static int setup_lttng_msg(struct command_ctx *cmd_ctx,
75 const void *payload_buf, size_t payload_len,
76 const void *cmd_header_buf, size_t cmd_header_len)
77 {
78 int ret = 0;
79 const size_t header_len = sizeof(struct lttcomm_lttng_msg);
80 const size_t cmd_header_offset = header_len;
81 const size_t payload_offset = cmd_header_offset + cmd_header_len;
82 const size_t total_msg_size = header_len + cmd_header_len + payload_len;
83
84 free(cmd_ctx->llm);
85 cmd_ctx->llm = zmalloc(total_msg_size);
86
87 if (cmd_ctx->llm == NULL) {
88 PERROR("zmalloc");
89 ret = -ENOMEM;
90 goto end;
91 }
92
93 /* Copy common data */
94 cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
95 cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
96 cmd_ctx->llm->cmd_header_size = cmd_header_len;
97 cmd_ctx->llm->data_size = payload_len;
98 cmd_ctx->lttng_msg_size = total_msg_size;
99
100 /* Copy command header */
101 if (cmd_header_len) {
102 memcpy(((uint8_t *) cmd_ctx->llm) + cmd_header_offset, cmd_header_buf,
103 cmd_header_len);
104 }
105
106 /* Copy payload */
107 if (payload_len) {
108 memcpy(((uint8_t *) cmd_ctx->llm) + payload_offset, payload_buf,
109 payload_len);
110 }
111
112 end:
113 return ret;
114 }
115
116 /*
117 * Start the thread_manage_consumer. This must be done after a lttng-consumerd
118 * exec or it will fail.
119 */
120 static int spawn_consumer_thread(struct consumer_data *consumer_data)
121 {
122 return launch_consumer_management_thread(consumer_data) ? 0 : -1;
123 }
124
125 /*
126 * Fork and exec a consumer daemon (consumerd).
127 *
128 * Return pid if successful else -1.
129 */
130 static pid_t spawn_consumerd(struct consumer_data *consumer_data)
131 {
132 int ret;
133 pid_t pid;
134 const char *consumer_to_use;
135 const char *verbosity;
136 struct stat st;
137
138 DBG("Spawning consumerd");
139
140 pid = fork();
141 if (pid == 0) {
142 /*
143 * Exec consumerd.
144 */
145 if (config.verbose_consumer) {
146 verbosity = "--verbose";
147 } else if (lttng_opt_quiet) {
148 verbosity = "--quiet";
149 } else {
150 verbosity = "";
151 }
152
153 switch (consumer_data->type) {
154 case LTTNG_CONSUMER_KERNEL:
155 /*
156 * Find out which consumerd to execute. We will first try the
157 * 64-bit path, then the sessiond's installation directory, and
158 * fallback on the 32-bit one,
159 */
160 DBG3("Looking for a kernel consumer at these locations:");
161 DBG3(" 1) %s", config.consumerd64_bin_path.value ? : "NULL");
162 DBG3(" 2) %s/%s", INSTALL_BIN_PATH, DEFAULT_CONSUMERD_FILE);
163 DBG3(" 3) %s", config.consumerd32_bin_path.value ? : "NULL");
164 if (stat(config.consumerd64_bin_path.value, &st) == 0) {
165 DBG3("Found location #1");
166 consumer_to_use = config.consumerd64_bin_path.value;
167 } else if (stat(INSTALL_BIN_PATH "/" DEFAULT_CONSUMERD_FILE, &st) == 0) {
168 DBG3("Found location #2");
169 consumer_to_use = INSTALL_BIN_PATH "/" DEFAULT_CONSUMERD_FILE;
170 } else if (config.consumerd32_bin_path.value &&
171 stat(config.consumerd32_bin_path.value, &st) == 0) {
172 DBG3("Found location #3");
173 consumer_to_use = config.consumerd32_bin_path.value;
174 } else {
175 DBG("Could not find any valid consumerd executable");
176 ret = -EINVAL;
177 goto error;
178 }
179 DBG("Using kernel consumer at: %s", consumer_to_use);
180 (void) execl(consumer_to_use,
181 "lttng-consumerd", verbosity, "-k",
182 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
183 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
184 "--group", config.tracing_group_name.value,
185 NULL);
186 break;
187 case LTTNG_CONSUMER64_UST:
188 {
189 if (config.consumerd64_lib_dir.value) {
190 const char *tmp;
191 size_t tmplen;
192 char *tmpnew;
193
194 tmp = lttng_secure_getenv("LD_LIBRARY_PATH");
195 if (!tmp) {
196 tmp = "";
197 }
198 tmplen = strlen(config.consumerd64_lib_dir.value) + 1 /* : */ + strlen(tmp);
199 tmpnew = zmalloc(tmplen + 1 /* \0 */);
200 if (!tmpnew) {
201 ret = -ENOMEM;
202 goto error;
203 }
204 strcat(tmpnew, config.consumerd64_lib_dir.value);
205 if (tmp[0] != '\0') {
206 strcat(tmpnew, ":");
207 strcat(tmpnew, tmp);
208 }
209 ret = setenv("LD_LIBRARY_PATH", tmpnew, 1);
210 free(tmpnew);
211 if (ret) {
212 ret = -errno;
213 goto error;
214 }
215 }
216 DBG("Using 64-bit UST consumer at: %s", config.consumerd64_bin_path.value);
217 (void) execl(config.consumerd64_bin_path.value, "lttng-consumerd", verbosity, "-u",
218 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
219 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
220 "--group", config.tracing_group_name.value,
221 NULL);
222 break;
223 }
224 case LTTNG_CONSUMER32_UST:
225 {
226 if (config.consumerd32_lib_dir.value) {
227 const char *tmp;
228 size_t tmplen;
229 char *tmpnew;
230
231 tmp = lttng_secure_getenv("LD_LIBRARY_PATH");
232 if (!tmp) {
233 tmp = "";
234 }
235 tmplen = strlen(config.consumerd32_lib_dir.value) + 1 /* : */ + strlen(tmp);
236 tmpnew = zmalloc(tmplen + 1 /* \0 */);
237 if (!tmpnew) {
238 ret = -ENOMEM;
239 goto error;
240 }
241 strcat(tmpnew, config.consumerd32_lib_dir.value);
242 if (tmp[0] != '\0') {
243 strcat(tmpnew, ":");
244 strcat(tmpnew, tmp);
245 }
246 ret = setenv("LD_LIBRARY_PATH", tmpnew, 1);
247 free(tmpnew);
248 if (ret) {
249 ret = -errno;
250 goto error;
251 }
252 }
253 DBG("Using 32-bit UST consumer at: %s", config.consumerd32_bin_path.value);
254 (void) execl(config.consumerd32_bin_path.value, "lttng-consumerd", verbosity, "-u",
255 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
256 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
257 "--group", config.tracing_group_name.value,
258 NULL);
259 break;
260 }
261 default:
262 ERR("unknown consumer type");
263 errno = 0;
264 }
265 if (errno != 0) {
266 PERROR("Consumer execl()");
267 }
268 /* Reaching this point, we got a failure on our execl(). */
269 exit(EXIT_FAILURE);
270 } else if (pid > 0) {
271 ret = pid;
272 } else {
273 PERROR("start consumer fork");
274 ret = -errno;
275 }
276 error:
277 return ret;
278 }
279
280 /*
281 * Spawn the consumerd daemon and session daemon thread.
282 */
283 static int start_consumerd(struct consumer_data *consumer_data)
284 {
285 int ret;
286
287 /*
288 * Set the listen() state on the socket since there is a possible race
289 * between the exec() of the consumer daemon and this call if place in the
290 * consumer thread. See bug #366 for more details.
291 */
292 ret = lttcomm_listen_unix_sock(consumer_data->err_sock);
293 if (ret < 0) {
294 goto error;
295 }
296
297 pthread_mutex_lock(&consumer_data->pid_mutex);
298 if (consumer_data->pid != 0) {
299 pthread_mutex_unlock(&consumer_data->pid_mutex);
300 goto end;
301 }
302
303 ret = spawn_consumerd(consumer_data);
304 if (ret < 0) {
305 ERR("Spawning consumerd failed");
306 pthread_mutex_unlock(&consumer_data->pid_mutex);
307 goto error;
308 }
309
310 /* Setting up the consumer_data pid */
311 consumer_data->pid = ret;
312 DBG2("Consumer pid %d", consumer_data->pid);
313 pthread_mutex_unlock(&consumer_data->pid_mutex);
314
315 DBG2("Spawning consumer control thread");
316 ret = spawn_consumer_thread(consumer_data);
317 if (ret < 0) {
318 ERR("Fatal error spawning consumer control thread");
319 goto error;
320 }
321
322 end:
323 return 0;
324
325 error:
326 /* Cleanup already created sockets on error. */
327 if (consumer_data->err_sock >= 0) {
328 int err;
329
330 err = close(consumer_data->err_sock);
331 if (err < 0) {
332 PERROR("close consumer data error socket");
333 }
334 }
335 return ret;
336 }
337
338 /*
339 * Copy consumer output from the tracing session to the domain session. The
340 * function also applies the right modification on a per domain basis for the
341 * trace files destination directory.
342 *
343 * Should *NOT* be called with RCU read-side lock held.
344 */
345 static int copy_session_consumer(int domain, struct ltt_session *session)
346 {
347 int ret;
348 const char *dir_name;
349 struct consumer_output *consumer;
350
351 assert(session);
352 assert(session->consumer);
353
354 switch (domain) {
355 case LTTNG_DOMAIN_KERNEL:
356 DBG3("Copying tracing session consumer output in kernel session");
357 /*
358 * XXX: We should audit the session creation and what this function
359 * does "extra" in order to avoid a destroy since this function is used
360 * in the domain session creation (kernel and ust) only. Same for UST
361 * domain.
362 */
363 if (session->kernel_session->consumer) {
364 consumer_output_put(session->kernel_session->consumer);
365 }
366 session->kernel_session->consumer =
367 consumer_copy_output(session->consumer);
368 /* Ease our life a bit for the next part */
369 consumer = session->kernel_session->consumer;
370 dir_name = DEFAULT_KERNEL_TRACE_DIR;
371 break;
372 case LTTNG_DOMAIN_JUL:
373 case LTTNG_DOMAIN_LOG4J:
374 case LTTNG_DOMAIN_PYTHON:
375 case LTTNG_DOMAIN_UST:
376 DBG3("Copying tracing session consumer output in UST session");
377 if (session->ust_session->consumer) {
378 consumer_output_put(session->ust_session->consumer);
379 }
380 session->ust_session->consumer =
381 consumer_copy_output(session->consumer);
382 /* Ease our life a bit for the next part */
383 consumer = session->ust_session->consumer;
384 dir_name = DEFAULT_UST_TRACE_DIR;
385 break;
386 default:
387 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
388 goto error;
389 }
390
391 /* Append correct directory to subdir */
392 ret = lttng_strncpy(consumer->domain_subdir, dir_name,
393 sizeof(consumer->domain_subdir));
394 if (ret) {
395 ret = LTTNG_ERR_UNK;
396 goto error;
397 }
398 DBG3("Copy session consumer subdir %s", consumer->domain_subdir);
399 ret = LTTNG_OK;
400
401 error:
402 return ret;
403 }
404
405 /*
406 * Create an UST session and add it to the session ust list.
407 *
408 * Should *NOT* be called with RCU read-side lock held.
409 */
410 static int create_ust_session(struct ltt_session *session,
411 const struct lttng_domain *domain)
412 {
413 int ret;
414 struct ltt_ust_session *lus = NULL;
415
416 assert(session);
417 assert(domain);
418 assert(session->consumer);
419
420 switch (domain->type) {
421 case LTTNG_DOMAIN_JUL:
422 case LTTNG_DOMAIN_LOG4J:
423 case LTTNG_DOMAIN_PYTHON:
424 case LTTNG_DOMAIN_UST:
425 break;
426 default:
427 ERR("Unknown UST domain on create session %d", domain->type);
428 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
429 goto error;
430 }
431
432 DBG("Creating UST session");
433
434 lus = trace_ust_create_session(session->id);
435 if (lus == NULL) {
436 ret = LTTNG_ERR_UST_SESS_FAIL;
437 goto error;
438 }
439
440 lus->uid = session->uid;
441 lus->gid = session->gid;
442 lus->output_traces = session->output_traces;
443 lus->snapshot_mode = session->snapshot_mode;
444 lus->live_timer_interval = session->live_timer;
445 session->ust_session = lus;
446 if (session->shm_path[0]) {
447 strncpy(lus->root_shm_path, session->shm_path,
448 sizeof(lus->root_shm_path));
449 lus->root_shm_path[sizeof(lus->root_shm_path) - 1] = '\0';
450 strncpy(lus->shm_path, session->shm_path,
451 sizeof(lus->shm_path));
452 lus->shm_path[sizeof(lus->shm_path) - 1] = '\0';
453 strncat(lus->shm_path, "/ust",
454 sizeof(lus->shm_path) - strlen(lus->shm_path) - 1);
455 }
456 /* Copy session output to the newly created UST session */
457 ret = copy_session_consumer(domain->type, session);
458 if (ret != LTTNG_OK) {
459 goto error;
460 }
461
462 return LTTNG_OK;
463
464 error:
465 free(lus);
466 session->ust_session = NULL;
467 return ret;
468 }
469
470 /*
471 * Create a kernel tracer session then create the default channel.
472 */
473 static int create_kernel_session(struct ltt_session *session)
474 {
475 int ret;
476
477 DBG("Creating kernel session");
478
479 ret = kernel_create_session(session);
480 if (ret < 0) {
481 ret = LTTNG_ERR_KERN_SESS_FAIL;
482 goto error_create;
483 }
484
485 /* Code flow safety */
486 assert(session->kernel_session);
487
488 /* Copy session output to the newly created Kernel session */
489 ret = copy_session_consumer(LTTNG_DOMAIN_KERNEL, session);
490 if (ret != LTTNG_OK) {
491 goto error;
492 }
493
494 session->kernel_session->uid = session->uid;
495 session->kernel_session->gid = session->gid;
496 session->kernel_session->output_traces = session->output_traces;
497 session->kernel_session->snapshot_mode = session->snapshot_mode;
498 session->kernel_session->is_live_session = session->live_timer != 0;
499
500 return LTTNG_OK;
501
502 error:
503 trace_kernel_destroy_session(session->kernel_session);
504 session->kernel_session = NULL;
505 error_create:
506 return ret;
507 }
508
509 /*
510 * Count number of session permitted by uid/gid.
511 */
512 static unsigned int lttng_sessions_count(uid_t uid, gid_t gid)
513 {
514 unsigned int i = 0;
515 struct ltt_session *session;
516 const struct ltt_session_list *session_list = session_get_list();
517
518 DBG("Counting number of available session for UID %d GID %d",
519 uid, gid);
520 cds_list_for_each_entry(session, &session_list->head, list) {
521 if (!session_get(session)) {
522 continue;
523 }
524 session_lock(session);
525 /* Only count the sessions the user can control. */
526 if (session_access_ok(session, uid, gid) &&
527 !session->destroyed) {
528 i++;
529 }
530 session_unlock(session);
531 session_put(session);
532 }
533 return i;
534 }
535
536 static int receive_userspace_probe(struct command_ctx *cmd_ctx, int sock,
537 int *sock_error, struct lttng_event *event)
538 {
539 int fd, ret;
540 struct lttng_userspace_probe_location *probe_location;
541 const struct lttng_userspace_probe_location_lookup_method *lookup = NULL;
542 struct lttng_dynamic_buffer probe_location_buffer;
543 struct lttng_buffer_view buffer_view;
544
545 /*
546 * Create a buffer to store the serialized version of the probe
547 * location.
548 */
549 lttng_dynamic_buffer_init(&probe_location_buffer);
550 ret = lttng_dynamic_buffer_set_size(&probe_location_buffer,
551 cmd_ctx->lsm->u.enable.userspace_probe_location_len);
552 if (ret) {
553 ret = LTTNG_ERR_NOMEM;
554 goto error;
555 }
556
557 /*
558 * Receive the probe location.
559 */
560 ret = lttcomm_recv_unix_sock(sock, probe_location_buffer.data,
561 probe_location_buffer.size);
562 if (ret <= 0) {
563 DBG("Nothing recv() from client var len data... continuing");
564 *sock_error = 1;
565 lttng_dynamic_buffer_reset(&probe_location_buffer);
566 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
567 goto error;
568 }
569
570 buffer_view = lttng_buffer_view_from_dynamic_buffer(
571 &probe_location_buffer, 0, probe_location_buffer.size);
572
573 /*
574 * Extract the probe location from the serialized version.
575 */
576 ret = lttng_userspace_probe_location_create_from_buffer(
577 &buffer_view, &probe_location);
578 if (ret < 0) {
579 WARN("Failed to create a userspace probe location from the received buffer");
580 lttng_dynamic_buffer_reset( &probe_location_buffer);
581 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
582 goto error;
583 }
584
585 /*
586 * Receive the file descriptor to the target binary from the client.
587 */
588 DBG("Receiving userspace probe target FD from client ...");
589 ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1);
590 if (ret <= 0) {
591 DBG("Nothing recv() from client userspace probe fd... continuing");
592 *sock_error = 1;
593 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
594 goto error;
595 }
596
597 /*
598 * Set the file descriptor received from the client through the unix
599 * socket in the probe location.
600 */
601 lookup = lttng_userspace_probe_location_get_lookup_method(probe_location);
602 if (!lookup) {
603 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
604 goto error;
605 }
606
607 /*
608 * From the kernel tracer's perspective, all userspace probe event types
609 * are all the same: a file and an offset.
610 */
611 switch (lttng_userspace_probe_location_lookup_method_get_type(lookup)) {
612 case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF:
613 ret = lttng_userspace_probe_location_function_set_binary_fd(
614 probe_location, fd);
615 break;
616 case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT:
617 ret = lttng_userspace_probe_location_tracepoint_set_binary_fd(
618 probe_location, fd);
619 break;
620 default:
621 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
622 goto error;
623 }
624
625 if (ret) {
626 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
627 goto error;
628 }
629
630 /* Attach the probe location to the event. */
631 ret = lttng_event_set_userspace_probe_location(event, probe_location);
632 if (ret) {
633 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
634 goto error;
635 }
636
637 lttng_dynamic_buffer_reset(&probe_location_buffer);
638 error:
639 return ret;
640 }
641
642 /*
643 * Version of setup_lttng_msg() without command header.
644 */
645 static int setup_lttng_msg_no_cmd_header(struct command_ctx *cmd_ctx,
646 void *payload_buf, size_t payload_len)
647 {
648 return setup_lttng_msg(cmd_ctx, payload_buf, payload_len, NULL, 0);
649 }
650
651 /*
652 * Free memory of a command context structure.
653 */
654 static void clean_command_ctx(struct command_ctx **cmd_ctx)
655 {
656 DBG("Clean command context structure");
657 if (*cmd_ctx) {
658 if ((*cmd_ctx)->llm) {
659 free((*cmd_ctx)->llm);
660 }
661 if ((*cmd_ctx)->lsm) {
662 free((*cmd_ctx)->lsm);
663 }
664 free(*cmd_ctx);
665 *cmd_ctx = NULL;
666 }
667 }
668
669 /*
670 * Check if the current kernel tracer supports the session rotation feature.
671 * Return 1 if it does, 0 otherwise.
672 */
673 static int check_rotate_compatible(void)
674 {
675 int ret = 1;
676
677 if (kernel_tracer_version.major != 2 || kernel_tracer_version.minor < 11) {
678 DBG("Kernel tracer version is not compatible with the rotation feature");
679 ret = 0;
680 }
681
682 return ret;
683 }
684
685 /*
686 * Send data on a unix socket using the liblttsessiondcomm API.
687 *
688 * Return lttcomm error code.
689 */
690 static int send_unix_sock(int sock, void *buf, size_t len)
691 {
692 /* Check valid length */
693 if (len == 0) {
694 return -1;
695 }
696
697 return lttcomm_send_unix_sock(sock, buf, len);
698 }
699
700 /*
701 * Process the command requested by the lttng client within the command
702 * context structure. This function make sure that the return structure (llm)
703 * is set and ready for transmission before returning.
704 *
705 * Return any error encountered or 0 for success.
706 *
707 * "sock" is only used for special-case var. len data.
708 * A command may assume the ownership of the socket, in which case its value
709 * should be set to -1.
710 *
711 * Should *NOT* be called with RCU read-side lock held.
712 */
713 static int process_client_msg(struct command_ctx *cmd_ctx, int *sock,
714 int *sock_error)
715 {
716 int ret = LTTNG_OK;
717 int need_tracing_session = 1;
718 int need_domain;
719
720 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
721
722 assert(!rcu_read_ongoing());
723
724 *sock_error = 0;
725
726 switch (cmd_ctx->lsm->cmd_type) {
727 case LTTNG_CREATE_SESSION_EXT:
728 case LTTNG_DESTROY_SESSION:
729 case LTTNG_LIST_SESSIONS:
730 case LTTNG_LIST_DOMAINS:
731 case LTTNG_START_TRACE:
732 case LTTNG_STOP_TRACE:
733 case LTTNG_DATA_PENDING:
734 case LTTNG_SNAPSHOT_ADD_OUTPUT:
735 case LTTNG_SNAPSHOT_DEL_OUTPUT:
736 case LTTNG_SNAPSHOT_LIST_OUTPUT:
737 case LTTNG_SNAPSHOT_RECORD:
738 case LTTNG_SAVE_SESSION:
739 case LTTNG_SET_SESSION_SHM_PATH:
740 case LTTNG_REGENERATE_METADATA:
741 case LTTNG_REGENERATE_STATEDUMP:
742 case LTTNG_REGISTER_TRIGGER:
743 case LTTNG_UNREGISTER_TRIGGER:
744 case LTTNG_ROTATE_SESSION:
745 case LTTNG_ROTATION_GET_INFO:
746 case LTTNG_ROTATION_SET_SCHEDULE:
747 case LTTNG_SESSION_LIST_ROTATION_SCHEDULES:
748 case LTTNG_CLEAR_SESSION:
749 need_domain = 0;
750 break;
751 default:
752 need_domain = 1;
753 }
754
755 if (config.no_kernel && need_domain
756 && cmd_ctx->lsm->domain.type == LTTNG_DOMAIN_KERNEL) {
757 if (!is_root) {
758 ret = LTTNG_ERR_NEED_ROOT_SESSIOND;
759 } else {
760 ret = LTTNG_ERR_KERN_NA;
761 }
762 goto error;
763 }
764
765 /* Deny register consumer if we already have a spawned consumer. */
766 if (cmd_ctx->lsm->cmd_type == LTTNG_REGISTER_CONSUMER) {
767 pthread_mutex_lock(&kconsumer_data.pid_mutex);
768 if (kconsumer_data.pid > 0) {
769 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
770 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
771 goto error;
772 }
773 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
774 }
775
776 /*
777 * Check for command that don't needs to allocate a returned payload. We do
778 * this here so we don't have to make the call for no payload at each
779 * command.
780 */
781 switch(cmd_ctx->lsm->cmd_type) {
782 case LTTNG_LIST_SESSIONS:
783 case LTTNG_LIST_TRACEPOINTS:
784 case LTTNG_LIST_TRACEPOINT_FIELDS:
785 case LTTNG_LIST_DOMAINS:
786 case LTTNG_LIST_CHANNELS:
787 case LTTNG_LIST_EVENTS:
788 case LTTNG_LIST_SYSCALLS:
789 case LTTNG_SESSION_LIST_ROTATION_SCHEDULES:
790 case LTTNG_PROCESS_ATTR_TRACKER_GET_POLICY:
791 case LTTNG_PROCESS_ATTR_TRACKER_GET_INCLUSION_SET:
792 case LTTNG_DATA_PENDING:
793 case LTTNG_ROTATE_SESSION:
794 case LTTNG_ROTATION_GET_INFO:
795 break;
796 default:
797 /* Setup lttng message with no payload */
798 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, NULL, 0);
799 if (ret < 0) {
800 /* This label does not try to unlock the session */
801 goto init_setup_error;
802 }
803 }
804
805 /* Commands that DO NOT need a session. */
806 switch (cmd_ctx->lsm->cmd_type) {
807 case LTTNG_CREATE_SESSION_EXT:
808 case LTTNG_LIST_SESSIONS:
809 case LTTNG_LIST_TRACEPOINTS:
810 case LTTNG_LIST_SYSCALLS:
811 case LTTNG_LIST_TRACEPOINT_FIELDS:
812 case LTTNG_SAVE_SESSION:
813 case LTTNG_REGISTER_TRIGGER:
814 case LTTNG_UNREGISTER_TRIGGER:
815 need_tracing_session = 0;
816 break;
817 default:
818 DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
819 /*
820 * We keep the session list lock across _all_ commands
821 * for now, because the per-session lock does not
822 * handle teardown properly.
823 */
824 session_lock_list();
825 cmd_ctx->session = session_find_by_name(cmd_ctx->lsm->session.name);
826 if (cmd_ctx->session == NULL) {
827 ret = LTTNG_ERR_SESS_NOT_FOUND;
828 goto error;
829 } else {
830 /* Acquire lock for the session */
831 session_lock(cmd_ctx->session);
832 }
833 break;
834 }
835
836 /*
837 * Commands that need a valid session but should NOT create one if none
838 * exists. Instead of creating one and destroying it when the command is
839 * handled, process that right before so we save some round trip in useless
840 * code path.
841 */
842 switch (cmd_ctx->lsm->cmd_type) {
843 case LTTNG_DISABLE_CHANNEL:
844 case LTTNG_DISABLE_EVENT:
845 switch (cmd_ctx->lsm->domain.type) {
846 case LTTNG_DOMAIN_KERNEL:
847 if (!cmd_ctx->session->kernel_session) {
848 ret = LTTNG_ERR_NO_CHANNEL;
849 goto error;
850 }
851 break;
852 case LTTNG_DOMAIN_JUL:
853 case LTTNG_DOMAIN_LOG4J:
854 case LTTNG_DOMAIN_PYTHON:
855 case LTTNG_DOMAIN_UST:
856 if (!cmd_ctx->session->ust_session) {
857 ret = LTTNG_ERR_NO_CHANNEL;
858 goto error;
859 }
860 break;
861 default:
862 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
863 goto error;
864 }
865 default:
866 break;
867 }
868
869 if (!need_domain) {
870 goto skip_domain;
871 }
872
873 /*
874 * Check domain type for specific "pre-action".
875 */
876 switch (cmd_ctx->lsm->domain.type) {
877 case LTTNG_DOMAIN_KERNEL:
878 if (!is_root) {
879 ret = LTTNG_ERR_NEED_ROOT_SESSIOND;
880 goto error;
881 }
882
883 /* Kernel tracer check */
884 if (!kernel_tracer_is_initialized()) {
885 /* Basically, load kernel tracer modules */
886 ret = init_kernel_tracer();
887 if (ret != 0) {
888 goto error;
889 }
890 }
891
892 /* Consumer is in an ERROR state. Report back to client */
893 if (uatomic_read(&kernel_consumerd_state) == CONSUMER_ERROR) {
894 ret = LTTNG_ERR_NO_KERNCONSUMERD;
895 goto error;
896 }
897
898 /* Need a session for kernel command */
899 if (need_tracing_session) {
900 if (cmd_ctx->session->kernel_session == NULL) {
901 ret = create_kernel_session(cmd_ctx->session);
902 if (ret != LTTNG_OK) {
903 ret = LTTNG_ERR_KERN_SESS_FAIL;
904 goto error;
905 }
906 }
907
908 /* Start the kernel consumer daemon */
909 pthread_mutex_lock(&kconsumer_data.pid_mutex);
910 if (kconsumer_data.pid == 0 &&
911 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
912 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
913 ret = start_consumerd(&kconsumer_data);
914 if (ret < 0) {
915 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
916 goto error;
917 }
918 uatomic_set(&kernel_consumerd_state, CONSUMER_STARTED);
919 } else {
920 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
921 }
922
923 /*
924 * The consumer was just spawned so we need to add the socket to
925 * the consumer output of the session if exist.
926 */
927 ret = consumer_create_socket(&kconsumer_data,
928 cmd_ctx->session->kernel_session->consumer);
929 if (ret < 0) {
930 goto error;
931 }
932 }
933
934 break;
935 case LTTNG_DOMAIN_JUL:
936 case LTTNG_DOMAIN_LOG4J:
937 case LTTNG_DOMAIN_PYTHON:
938 case LTTNG_DOMAIN_UST:
939 {
940 if (!ust_app_supported()) {
941 ret = LTTNG_ERR_NO_UST;
942 goto error;
943 }
944 /* Consumer is in an ERROR state. Report back to client */
945 if (uatomic_read(&ust_consumerd_state) == CONSUMER_ERROR) {
946 ret = LTTNG_ERR_NO_USTCONSUMERD;
947 goto error;
948 }
949
950 if (need_tracing_session) {
951 /* Create UST session if none exist. */
952 if (cmd_ctx->session->ust_session == NULL) {
953 ret = create_ust_session(cmd_ctx->session,
954 ALIGNED_CONST_PTR(cmd_ctx->lsm->domain));
955 if (ret != LTTNG_OK) {
956 goto error;
957 }
958 }
959
960 /* Start the UST consumer daemons */
961 /* 64-bit */
962 pthread_mutex_lock(&ustconsumer64_data.pid_mutex);
963 if (config.consumerd64_bin_path.value &&
964 ustconsumer64_data.pid == 0 &&
965 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
966 pthread_mutex_unlock(&ustconsumer64_data.pid_mutex);
967 ret = start_consumerd(&ustconsumer64_data);
968 if (ret < 0) {
969 ret = LTTNG_ERR_UST_CONSUMER64_FAIL;
970 uatomic_set(&ust_consumerd64_fd, -EINVAL);
971 goto error;
972 }
973
974 uatomic_set(&ust_consumerd64_fd, ustconsumer64_data.cmd_sock);
975 uatomic_set(&ust_consumerd_state, CONSUMER_STARTED);
976 } else {
977 pthread_mutex_unlock(&ustconsumer64_data.pid_mutex);
978 }
979
980 /*
981 * Setup socket for consumer 64 bit. No need for atomic access
982 * since it was set above and can ONLY be set in this thread.
983 */
984 ret = consumer_create_socket(&ustconsumer64_data,
985 cmd_ctx->session->ust_session->consumer);
986 if (ret < 0) {
987 goto error;
988 }
989
990 /* 32-bit */
991 pthread_mutex_lock(&ustconsumer32_data.pid_mutex);
992 if (config.consumerd32_bin_path.value &&
993 ustconsumer32_data.pid == 0 &&
994 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
995 pthread_mutex_unlock(&ustconsumer32_data.pid_mutex);
996 ret = start_consumerd(&ustconsumer32_data);
997 if (ret < 0) {
998 ret = LTTNG_ERR_UST_CONSUMER32_FAIL;
999 uatomic_set(&ust_consumerd32_fd, -EINVAL);
1000 goto error;
1001 }
1002
1003 uatomic_set(&ust_consumerd32_fd, ustconsumer32_data.cmd_sock);
1004 uatomic_set(&ust_consumerd_state, CONSUMER_STARTED);
1005 } else {
1006 pthread_mutex_unlock(&ustconsumer32_data.pid_mutex);
1007 }
1008
1009 /*
1010 * Setup socket for consumer 32 bit. No need for atomic access
1011 * since it was set above and can ONLY be set in this thread.
1012 */
1013 ret = consumer_create_socket(&ustconsumer32_data,
1014 cmd_ctx->session->ust_session->consumer);
1015 if (ret < 0) {
1016 goto error;
1017 }
1018 }
1019 break;
1020 }
1021 default:
1022 break;
1023 }
1024 skip_domain:
1025
1026 /* Validate consumer daemon state when start/stop trace command */
1027 if (cmd_ctx->lsm->cmd_type == LTTNG_START_TRACE ||
1028 cmd_ctx->lsm->cmd_type == LTTNG_STOP_TRACE) {
1029 switch (cmd_ctx->lsm->domain.type) {
1030 case LTTNG_DOMAIN_NONE:
1031 break;
1032 case LTTNG_DOMAIN_JUL:
1033 case LTTNG_DOMAIN_LOG4J:
1034 case LTTNG_DOMAIN_PYTHON:
1035 case LTTNG_DOMAIN_UST:
1036 if (uatomic_read(&ust_consumerd_state) != CONSUMER_STARTED) {
1037 ret = LTTNG_ERR_NO_USTCONSUMERD;
1038 goto error;
1039 }
1040 break;
1041 case LTTNG_DOMAIN_KERNEL:
1042 if (uatomic_read(&kernel_consumerd_state) != CONSUMER_STARTED) {
1043 ret = LTTNG_ERR_NO_KERNCONSUMERD;
1044 goto error;
1045 }
1046 break;
1047 default:
1048 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1049 goto error;
1050 }
1051 }
1052
1053 /*
1054 * Check that the UID or GID match that of the tracing session.
1055 * The root user can interact with all sessions.
1056 */
1057 if (need_tracing_session) {
1058 if (!session_access_ok(cmd_ctx->session,
1059 LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
1060 LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds)) ||
1061 cmd_ctx->session->destroyed) {
1062 ret = LTTNG_ERR_EPERM;
1063 goto error;
1064 }
1065 }
1066
1067 /*
1068 * Send relayd information to consumer as soon as we have a domain and a
1069 * session defined.
1070 */
1071 if (cmd_ctx->session && need_domain) {
1072 /*
1073 * Setup relayd if not done yet. If the relayd information was already
1074 * sent to the consumer, this call will gracefully return.
1075 */
1076 ret = cmd_setup_relayd(cmd_ctx->session);
1077 if (ret != LTTNG_OK) {
1078 goto error;
1079 }
1080 }
1081
1082 /* Process by command type */
1083 switch (cmd_ctx->lsm->cmd_type) {
1084 case LTTNG_ADD_CONTEXT:
1085 {
1086 /*
1087 * An LTTNG_ADD_CONTEXT command might have a supplementary
1088 * payload if the context being added is an application context.
1089 */
1090 if (cmd_ctx->lsm->u.context.ctx.ctx ==
1091 LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
1092 char *provider_name = NULL, *context_name = NULL;
1093 size_t provider_name_len =
1094 cmd_ctx->lsm->u.context.provider_name_len;
1095 size_t context_name_len =
1096 cmd_ctx->lsm->u.context.context_name_len;
1097
1098 if (provider_name_len == 0 || context_name_len == 0) {
1099 /*
1100 * Application provider and context names MUST
1101 * be provided.
1102 */
1103 ret = -LTTNG_ERR_INVALID;
1104 goto error;
1105 }
1106
1107 provider_name = zmalloc(provider_name_len + 1);
1108 if (!provider_name) {
1109 ret = -LTTNG_ERR_NOMEM;
1110 goto error;
1111 }
1112 cmd_ctx->lsm->u.context.ctx.u.app_ctx.provider_name =
1113 provider_name;
1114
1115 context_name = zmalloc(context_name_len + 1);
1116 if (!context_name) {
1117 ret = -LTTNG_ERR_NOMEM;
1118 goto error_add_context;
1119 }
1120 cmd_ctx->lsm->u.context.ctx.u.app_ctx.ctx_name =
1121 context_name;
1122
1123 ret = lttcomm_recv_unix_sock(*sock, provider_name,
1124 provider_name_len);
1125 if (ret < 0) {
1126 goto error_add_context;
1127 }
1128
1129 ret = lttcomm_recv_unix_sock(*sock, context_name,
1130 context_name_len);
1131 if (ret < 0) {
1132 goto error_add_context;
1133 }
1134 }
1135
1136 /*
1137 * cmd_add_context assumes ownership of the provider and context
1138 * names.
1139 */
1140 ret = cmd_add_context(cmd_ctx->session,
1141 cmd_ctx->lsm->domain.type,
1142 cmd_ctx->lsm->u.context.channel_name,
1143 ALIGNED_CONST_PTR(cmd_ctx->lsm->u.context.ctx),
1144 kernel_poll_pipe[1]);
1145
1146 cmd_ctx->lsm->u.context.ctx.u.app_ctx.provider_name = NULL;
1147 cmd_ctx->lsm->u.context.ctx.u.app_ctx.ctx_name = NULL;
1148 error_add_context:
1149 free(cmd_ctx->lsm->u.context.ctx.u.app_ctx.provider_name);
1150 free(cmd_ctx->lsm->u.context.ctx.u.app_ctx.ctx_name);
1151 if (ret < 0) {
1152 goto error;
1153 }
1154 break;
1155 }
1156 case LTTNG_DISABLE_CHANNEL:
1157 {
1158 ret = cmd_disable_channel(cmd_ctx->session, cmd_ctx->lsm->domain.type,
1159 cmd_ctx->lsm->u.disable.channel_name);
1160 break;
1161 }
1162 case LTTNG_DISABLE_EVENT:
1163 {
1164
1165 /*
1166 * FIXME: handle filter; for now we just receive the filter's
1167 * bytecode along with the filter expression which are sent by
1168 * liblttng-ctl and discard them.
1169 *
1170 * This fixes an issue where the client may block while sending
1171 * the filter payload and encounter an error because the session
1172 * daemon closes the socket without ever handling this data.
1173 */
1174 size_t count = cmd_ctx->lsm->u.disable.expression_len +
1175 cmd_ctx->lsm->u.disable.bytecode_len;
1176
1177 if (count) {
1178 char data[LTTNG_FILTER_MAX_LEN];
1179
1180 DBG("Discarding disable event command payload of size %zu", count);
1181 while (count) {
1182 ret = lttcomm_recv_unix_sock(*sock, data,
1183 count > sizeof(data) ? sizeof(data) : count);
1184 if (ret < 0) {
1185 goto error;
1186 }
1187
1188 count -= (size_t) ret;
1189 }
1190 }
1191 ret = cmd_disable_event(cmd_ctx->session, cmd_ctx->lsm->domain.type,
1192 cmd_ctx->lsm->u.disable.channel_name,
1193 ALIGNED_CONST_PTR(cmd_ctx->lsm->u.disable.event));
1194 break;
1195 }
1196 case LTTNG_ENABLE_CHANNEL:
1197 {
1198 cmd_ctx->lsm->u.channel.chan.attr.extended.ptr =
1199 (struct lttng_channel_extended *) &cmd_ctx->lsm->u.channel.extended;
1200 ret = cmd_enable_channel(cmd_ctx->session,
1201 ALIGNED_CONST_PTR(cmd_ctx->lsm->domain),
1202 ALIGNED_CONST_PTR(cmd_ctx->lsm->u.channel.chan),
1203 kernel_poll_pipe[1]);
1204 break;
1205 }
1206 case LTTNG_PROCESS_ATTR_TRACKER_ADD_INCLUDE_VALUE:
1207 case LTTNG_PROCESS_ATTR_TRACKER_REMOVE_INCLUDE_VALUE:
1208 {
1209 struct lttng_dynamic_buffer payload;
1210 struct lttng_buffer_view payload_view;
1211 const bool add_value =
1212 cmd_ctx->lsm->cmd_type ==
1213 LTTNG_PROCESS_ATTR_TRACKER_ADD_INCLUDE_VALUE;
1214 const size_t name_len =
1215 cmd_ctx->lsm->u.process_attr_tracker_add_remove_include_value
1216 .name_len;
1217 const enum lttng_domain_type domain_type =
1218 (enum lttng_domain_type)
1219 cmd_ctx->lsm->domain.type;
1220 const enum lttng_process_attr process_attr =
1221 (enum lttng_process_attr) cmd_ctx->lsm->u
1222 .process_attr_tracker_add_remove_include_value
1223 .process_attr;
1224 const enum lttng_process_attr_value_type value_type =
1225 (enum lttng_process_attr_value_type) cmd_ctx
1226 ->lsm->u
1227 .process_attr_tracker_add_remove_include_value
1228 .value_type;
1229 struct process_attr_value *value;
1230 enum lttng_error_code ret_code;
1231
1232 /* Receive remaining variable length payload if applicable. */
1233 if (name_len > LOGIN_NAME_MAX) {
1234 /*
1235 * POSIX mandates user and group names that are at least
1236 * 8 characters long. Note that although shadow-utils
1237 * (useradd, groupaadd, etc.) use 32 chars as their
1238 * limit (from bits/utmp.h, UT_NAMESIZE),
1239 * LOGIN_NAME_MAX is defined to 256.
1240 */
1241 ERR("Rejecting process attribute tracker value %s as the provided exceeds the maximal allowed length: argument length = %zu, maximal length = %d",
1242 add_value ? "addition" : "removal",
1243 name_len, LOGIN_NAME_MAX);
1244 ret = LTTNG_ERR_INVALID;
1245 goto error;
1246 }
1247
1248 lttng_dynamic_buffer_init(&payload);
1249 if (name_len != 0) {
1250 /*
1251 * Receive variable payload for user/group name
1252 * arguments.
1253 */
1254 ret = lttng_dynamic_buffer_set_size(&payload, name_len);
1255 if (ret) {
1256 ERR("Failed to allocate buffer to receive payload of %s process attribute tracker value argument",
1257 add_value ? "add" : "remove");
1258 ret = LTTNG_ERR_NOMEM;
1259 goto error_add_remove_tracker_value;
1260 }
1261
1262 ret = lttcomm_recv_unix_sock(
1263 *sock, payload.data, name_len);
1264 if (ret <= 0) {
1265 ERR("Failed to receive payload of %s process attribute tracker value argument",
1266 add_value ? "add" : "remove");
1267 *sock_error = 1;
1268 ret = LTTNG_ERR_INVALID_PROTOCOL;
1269 goto error_add_remove_tracker_value;
1270 }
1271 }
1272
1273 payload_view = lttng_buffer_view_from_dynamic_buffer(
1274 &payload, 0, name_len);
1275 /*
1276 * Validate the value type and domains are legal for the process
1277 * attribute tracker that is specified and convert the value to
1278 * add/remove to the internal sessiond representation.
1279 */
1280 ret_code = process_attr_value_from_comm(domain_type,
1281 process_attr, value_type,
1282 &cmd_ctx->lsm->u.process_attr_tracker_add_remove_include_value
1283 .integral_value,
1284 &payload_view, &value);
1285 if (ret_code != LTTNG_OK) {
1286 ret = ret_code;
1287 goto error_add_remove_tracker_value;
1288 }
1289
1290 if (add_value) {
1291 ret = cmd_process_attr_tracker_inclusion_set_add_value(
1292 cmd_ctx->session, domain_type,
1293 process_attr, value);
1294 } else {
1295 ret = cmd_process_attr_tracker_inclusion_set_remove_value(
1296 cmd_ctx->session, domain_type,
1297 process_attr, value);
1298 }
1299 process_attr_value_destroy(value);
1300 error_add_remove_tracker_value:
1301 lttng_dynamic_buffer_reset(&payload);
1302 break;
1303 }
1304 case LTTNG_PROCESS_ATTR_TRACKER_GET_POLICY:
1305 {
1306 enum lttng_tracking_policy tracking_policy;
1307 const enum lttng_domain_type domain_type =
1308 (enum lttng_domain_type)
1309 cmd_ctx->lsm->domain.type;
1310 const enum lttng_process_attr process_attr =
1311 (enum lttng_process_attr) cmd_ctx->lsm->u
1312 .process_attr_tracker_get_tracking_policy
1313 .process_attr;
1314
1315 ret = cmd_process_attr_tracker_get_tracking_policy(
1316 cmd_ctx->session, domain_type, process_attr,
1317 &tracking_policy);
1318 if (ret != LTTNG_OK) {
1319 goto error;
1320 }
1321
1322 ret = setup_lttng_msg_no_cmd_header(cmd_ctx,
1323 &(uint32_t){tracking_policy}, sizeof(uint32_t));
1324 if (ret < 0) {
1325 ret = LTTNG_ERR_NOMEM;
1326 goto error;
1327 }
1328 ret = LTTNG_OK;
1329 break;
1330 }
1331 case LTTNG_PROCESS_ATTR_TRACKER_SET_POLICY:
1332 {
1333 const enum lttng_tracking_policy tracking_policy =
1334 (enum lttng_tracking_policy) cmd_ctx->lsm->u
1335 .process_attr_tracker_set_tracking_policy
1336 .tracking_policy;
1337 const enum lttng_domain_type domain_type =
1338 (enum lttng_domain_type)
1339 cmd_ctx->lsm->domain.type;
1340 const enum lttng_process_attr process_attr =
1341 (enum lttng_process_attr) cmd_ctx->lsm->u
1342 .process_attr_tracker_set_tracking_policy
1343 .process_attr;
1344
1345 ret = cmd_process_attr_tracker_set_tracking_policy(
1346 cmd_ctx->session, domain_type, process_attr,
1347 tracking_policy);
1348 if (ret != LTTNG_OK) {
1349 goto error;
1350 }
1351 break;
1352 }
1353 case LTTNG_PROCESS_ATTR_TRACKER_GET_INCLUSION_SET:
1354 {
1355 struct lttng_process_attr_values *values;
1356 struct lttng_dynamic_buffer reply;
1357 const enum lttng_domain_type domain_type =
1358 (enum lttng_domain_type)
1359 cmd_ctx->lsm->domain.type;
1360 const enum lttng_process_attr process_attr =
1361 (enum lttng_process_attr) cmd_ctx->lsm->u
1362 .process_attr_tracker_get_inclusion_set
1363 .process_attr;
1364
1365 ret = cmd_process_attr_tracker_get_inclusion_set(
1366 cmd_ctx->session, domain_type, process_attr,
1367 &values);
1368 if (ret != LTTNG_OK) {
1369 goto error;
1370 }
1371
1372 lttng_dynamic_buffer_init(&reply);
1373 ret = lttng_process_attr_values_serialize(values, &reply);
1374 if (ret < 0) {
1375 goto error_tracker_get_inclusion_set;
1376 }
1377
1378 ret = setup_lttng_msg_no_cmd_header(
1379 cmd_ctx, reply.data, reply.size);
1380 if (ret < 0) {
1381 ret = LTTNG_ERR_NOMEM;
1382 goto error_tracker_get_inclusion_set;
1383 }
1384 ret = LTTNG_OK;
1385
1386 error_tracker_get_inclusion_set:
1387 lttng_process_attr_values_destroy(values);
1388 lttng_dynamic_buffer_reset(&reply);
1389 break;
1390 }
1391 case LTTNG_ENABLE_EVENT:
1392 {
1393 struct lttng_event *ev = NULL;
1394 struct lttng_event_exclusion *exclusion = NULL;
1395 struct lttng_filter_bytecode *bytecode = NULL;
1396 char *filter_expression = NULL;
1397
1398 /* Handle exclusion events and receive it from the client. */
1399 if (cmd_ctx->lsm->u.enable.exclusion_count > 0) {
1400 size_t count = cmd_ctx->lsm->u.enable.exclusion_count;
1401
1402 exclusion = zmalloc(sizeof(struct lttng_event_exclusion) +
1403 (count * LTTNG_SYMBOL_NAME_LEN));
1404 if (!exclusion) {
1405 ret = LTTNG_ERR_EXCLUSION_NOMEM;
1406 goto error;
1407 }
1408
1409 DBG("Receiving var len exclusion event list from client ...");
1410 exclusion->count = count;
1411 ret = lttcomm_recv_unix_sock(*sock, exclusion->names,
1412 count * LTTNG_SYMBOL_NAME_LEN);
1413 if (ret <= 0) {
1414 DBG("Nothing recv() from client var len data... continuing");
1415 *sock_error = 1;
1416 free(exclusion);
1417 ret = LTTNG_ERR_EXCLUSION_INVAL;
1418 goto error;
1419 }
1420 }
1421
1422 /* Get filter expression from client. */
1423 if (cmd_ctx->lsm->u.enable.expression_len > 0) {
1424 size_t expression_len =
1425 cmd_ctx->lsm->u.enable.expression_len;
1426
1427 if (expression_len > LTTNG_FILTER_MAX_LEN) {
1428 ret = LTTNG_ERR_FILTER_INVAL;
1429 free(exclusion);
1430 goto error;
1431 }
1432
1433 filter_expression = zmalloc(expression_len);
1434 if (!filter_expression) {
1435 free(exclusion);
1436 ret = LTTNG_ERR_FILTER_NOMEM;
1437 goto error;
1438 }
1439
1440 /* Receive var. len. data */
1441 DBG("Receiving var len filter's expression from client ...");
1442 ret = lttcomm_recv_unix_sock(*sock, filter_expression,
1443 expression_len);
1444 if (ret <= 0) {
1445 DBG("Nothing recv() from client var len data... continuing");
1446 *sock_error = 1;
1447 free(filter_expression);
1448 free(exclusion);
1449 ret = LTTNG_ERR_FILTER_INVAL;
1450 goto error;
1451 }
1452 }
1453
1454 /* Handle filter and get bytecode from client. */
1455 if (cmd_ctx->lsm->u.enable.bytecode_len > 0) {
1456 size_t bytecode_len = cmd_ctx->lsm->u.enable.bytecode_len;
1457
1458 if (bytecode_len > LTTNG_FILTER_MAX_LEN) {
1459 ret = LTTNG_ERR_FILTER_INVAL;
1460 free(filter_expression);
1461 free(exclusion);
1462 goto error;
1463 }
1464
1465 bytecode = zmalloc(bytecode_len);
1466 if (!bytecode) {
1467 free(filter_expression);
1468 free(exclusion);
1469 ret = LTTNG_ERR_FILTER_NOMEM;
1470 goto error;
1471 }
1472
1473 /* Receive var. len. data */
1474 DBG("Receiving var len filter's bytecode from client ...");
1475 ret = lttcomm_recv_unix_sock(*sock, bytecode, bytecode_len);
1476 if (ret <= 0) {
1477 DBG("Nothing recv() from client var len data... continuing");
1478 *sock_error = 1;
1479 free(filter_expression);
1480 free(bytecode);
1481 free(exclusion);
1482 ret = LTTNG_ERR_FILTER_INVAL;
1483 goto error;
1484 }
1485
1486 if ((bytecode->len + sizeof(*bytecode)) != bytecode_len) {
1487 free(filter_expression);
1488 free(bytecode);
1489 free(exclusion);
1490 ret = LTTNG_ERR_FILTER_INVAL;
1491 goto error;
1492 }
1493 }
1494
1495 ev = lttng_event_copy(ALIGNED_CONST_PTR(cmd_ctx->lsm->u.enable.event));
1496 if (!ev) {
1497 DBG("Failed to copy event: %s",
1498 cmd_ctx->lsm->u.enable.event.name);
1499 free(filter_expression);
1500 free(bytecode);
1501 free(exclusion);
1502 ret = LTTNG_ERR_NOMEM;
1503 goto error;
1504 }
1505
1506
1507 if (cmd_ctx->lsm->u.enable.userspace_probe_location_len > 0) {
1508 /* Expect a userspace probe description. */
1509 ret = receive_userspace_probe(cmd_ctx, *sock, sock_error, ev);
1510 if (ret) {
1511 free(filter_expression);
1512 free(bytecode);
1513 free(exclusion);
1514 lttng_event_destroy(ev);
1515 goto error;
1516 }
1517 }
1518
1519 ret = cmd_enable_event(cmd_ctx->session,
1520 ALIGNED_CONST_PTR(cmd_ctx->lsm->domain),
1521 cmd_ctx->lsm->u.enable.channel_name,
1522 ev,
1523 filter_expression, bytecode, exclusion,
1524 kernel_poll_pipe[1]);
1525 lttng_event_destroy(ev);
1526 break;
1527 }
1528 case LTTNG_LIST_TRACEPOINTS:
1529 {
1530 struct lttng_event *events;
1531 ssize_t nb_events;
1532
1533 session_lock_list();
1534 nb_events = cmd_list_tracepoints(cmd_ctx->lsm->domain.type, &events);
1535 session_unlock_list();
1536 if (nb_events < 0) {
1537 /* Return value is a negative lttng_error_code. */
1538 ret = -nb_events;
1539 goto error;
1540 }
1541
1542 /*
1543 * Setup lttng message with payload size set to the event list size in
1544 * bytes and then copy list into the llm payload.
1545 */
1546 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, events,
1547 sizeof(struct lttng_event) * nb_events);
1548 free(events);
1549
1550 if (ret < 0) {
1551 goto setup_error;
1552 }
1553
1554 ret = LTTNG_OK;
1555 break;
1556 }
1557 case LTTNG_LIST_TRACEPOINT_FIELDS:
1558 {
1559 struct lttng_event_field *fields;
1560 ssize_t nb_fields;
1561
1562 session_lock_list();
1563 nb_fields = cmd_list_tracepoint_fields(cmd_ctx->lsm->domain.type,
1564 &fields);
1565 session_unlock_list();
1566 if (nb_fields < 0) {
1567 /* Return value is a negative lttng_error_code. */
1568 ret = -nb_fields;
1569 goto error;
1570 }
1571
1572 /*
1573 * Setup lttng message with payload size set to the event list size in
1574 * bytes and then copy list into the llm payload.
1575 */
1576 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, fields,
1577 sizeof(struct lttng_event_field) * nb_fields);
1578 free(fields);
1579
1580 if (ret < 0) {
1581 goto setup_error;
1582 }
1583
1584 ret = LTTNG_OK;
1585 break;
1586 }
1587 case LTTNG_LIST_SYSCALLS:
1588 {
1589 struct lttng_event *events;
1590 ssize_t nb_events;
1591
1592 nb_events = cmd_list_syscalls(&events);
1593 if (nb_events < 0) {
1594 /* Return value is a negative lttng_error_code. */
1595 ret = -nb_events;
1596 goto error;
1597 }
1598
1599 /*
1600 * Setup lttng message with payload size set to the event list size in
1601 * bytes and then copy list into the llm payload.
1602 */
1603 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, events,
1604 sizeof(struct lttng_event) * nb_events);
1605 free(events);
1606
1607 if (ret < 0) {
1608 goto setup_error;
1609 }
1610
1611 ret = LTTNG_OK;
1612 break;
1613 }
1614 case LTTNG_SET_CONSUMER_URI:
1615 {
1616 size_t nb_uri, len;
1617 struct lttng_uri *uris;
1618
1619 nb_uri = cmd_ctx->lsm->u.uri.size;
1620 len = nb_uri * sizeof(struct lttng_uri);
1621
1622 if (nb_uri == 0) {
1623 ret = LTTNG_ERR_INVALID;
1624 goto error;
1625 }
1626
1627 uris = zmalloc(len);
1628 if (uris == NULL) {
1629 ret = LTTNG_ERR_FATAL;
1630 goto error;
1631 }
1632
1633 /* Receive variable len data */
1634 DBG("Receiving %zu URI(s) from client ...", nb_uri);
1635 ret = lttcomm_recv_unix_sock(*sock, uris, len);
1636 if (ret <= 0) {
1637 DBG("No URIs received from client... continuing");
1638 *sock_error = 1;
1639 ret = LTTNG_ERR_SESSION_FAIL;
1640 free(uris);
1641 goto error;
1642 }
1643
1644 ret = cmd_set_consumer_uri(cmd_ctx->session, nb_uri, uris);
1645 free(uris);
1646 if (ret != LTTNG_OK) {
1647 goto error;
1648 }
1649
1650
1651 break;
1652 }
1653 case LTTNG_START_TRACE:
1654 {
1655 /*
1656 * On the first start, if we have a kernel session and we have
1657 * enabled time or size-based rotations, we have to make sure
1658 * the kernel tracer supports it.
1659 */
1660 if (!cmd_ctx->session->has_been_started && \
1661 cmd_ctx->session->kernel_session && \
1662 (cmd_ctx->session->rotate_timer_period || \
1663 cmd_ctx->session->rotate_size) && \
1664 !check_rotate_compatible()) {
1665 DBG("Kernel tracer version is not compatible with the rotation feature");
1666 ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
1667 goto error;
1668 }
1669 ret = cmd_start_trace(cmd_ctx->session);
1670 break;
1671 }
1672 case LTTNG_STOP_TRACE:
1673 {
1674 ret = cmd_stop_trace(cmd_ctx->session);
1675 break;
1676 }
1677 case LTTNG_DESTROY_SESSION:
1678 {
1679 ret = cmd_destroy_session(cmd_ctx->session,
1680 notification_thread_handle,
1681 sock);
1682 break;
1683 }
1684 case LTTNG_LIST_DOMAINS:
1685 {
1686 ssize_t nb_dom;
1687 struct lttng_domain *domains = NULL;
1688
1689 nb_dom = cmd_list_domains(cmd_ctx->session, &domains);
1690 if (nb_dom < 0) {
1691 /* Return value is a negative lttng_error_code. */
1692 ret = -nb_dom;
1693 goto error;
1694 }
1695
1696 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, domains,
1697 nb_dom * sizeof(struct lttng_domain));
1698 free(domains);
1699
1700 if (ret < 0) {
1701 goto setup_error;
1702 }
1703
1704 ret = LTTNG_OK;
1705 break;
1706 }
1707 case LTTNG_LIST_CHANNELS:
1708 {
1709 ssize_t payload_size;
1710 struct lttng_channel *channels = NULL;
1711
1712 payload_size = cmd_list_channels(cmd_ctx->lsm->domain.type,
1713 cmd_ctx->session, &channels);
1714 if (payload_size < 0) {
1715 /* Return value is a negative lttng_error_code. */
1716 ret = -payload_size;
1717 goto error;
1718 }
1719
1720 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, channels,
1721 payload_size);
1722 free(channels);
1723
1724 if (ret < 0) {
1725 goto setup_error;
1726 }
1727
1728 ret = LTTNG_OK;
1729 break;
1730 }
1731 case LTTNG_LIST_EVENTS:
1732 {
1733 ssize_t nb_event;
1734 struct lttng_event *events = NULL;
1735 struct lttcomm_event_command_header cmd_header;
1736 size_t total_size;
1737
1738 memset(&cmd_header, 0, sizeof(cmd_header));
1739 /* Extended infos are included at the end of events */
1740 nb_event = cmd_list_events(cmd_ctx->lsm->domain.type,
1741 cmd_ctx->session, cmd_ctx->lsm->u.list.channel_name,
1742 &events, &total_size);
1743
1744 if (nb_event < 0) {
1745 /* Return value is a negative lttng_error_code. */
1746 ret = -nb_event;
1747 goto error;
1748 }
1749
1750 cmd_header.nb_events = nb_event;
1751 ret = setup_lttng_msg(cmd_ctx, events, total_size,
1752 &cmd_header, sizeof(cmd_header));
1753 free(events);
1754
1755 if (ret < 0) {
1756 goto setup_error;
1757 }
1758
1759 ret = LTTNG_OK;
1760 break;
1761 }
1762 case LTTNG_LIST_SESSIONS:
1763 {
1764 unsigned int nr_sessions;
1765 void *sessions_payload;
1766 size_t payload_len;
1767
1768 session_lock_list();
1769 nr_sessions = lttng_sessions_count(
1770 LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
1771 LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds));
1772
1773 payload_len = (sizeof(struct lttng_session) * nr_sessions) +
1774 (sizeof(struct lttng_session_extended) * nr_sessions);
1775 sessions_payload = zmalloc(payload_len);
1776
1777 if (!sessions_payload) {
1778 session_unlock_list();
1779 ret = -ENOMEM;
1780 goto setup_error;
1781 }
1782
1783 cmd_list_lttng_sessions(sessions_payload, nr_sessions,
1784 LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
1785 LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds));
1786 session_unlock_list();
1787
1788 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, sessions_payload,
1789 payload_len);
1790 free(sessions_payload);
1791
1792 if (ret < 0) {
1793 goto setup_error;
1794 }
1795
1796 ret = LTTNG_OK;
1797 break;
1798 }
1799 case LTTNG_REGISTER_CONSUMER:
1800 {
1801 struct consumer_data *cdata;
1802
1803 switch (cmd_ctx->lsm->domain.type) {
1804 case LTTNG_DOMAIN_KERNEL:
1805 cdata = &kconsumer_data;
1806 break;
1807 default:
1808 ret = LTTNG_ERR_UND;
1809 goto error;
1810 }
1811
1812 ret = cmd_register_consumer(cmd_ctx->session, cmd_ctx->lsm->domain.type,
1813 cmd_ctx->lsm->u.reg.path, cdata);
1814 break;
1815 }
1816 case LTTNG_DATA_PENDING:
1817 {
1818 int pending_ret;
1819 uint8_t pending_ret_byte;
1820
1821 pending_ret = cmd_data_pending(cmd_ctx->session);
1822
1823 /*
1824 * FIXME
1825 *
1826 * This function may returns 0 or 1 to indicate whether or not
1827 * there is data pending. In case of error, it should return an
1828 * LTTNG_ERR code. However, some code paths may still return
1829 * a nondescript error code, which we handle by returning an
1830 * "unknown" error.
1831 */
1832 if (pending_ret == 0 || pending_ret == 1) {
1833 /*
1834 * ret will be set to LTTNG_OK at the end of
1835 * this function.
1836 */
1837 } else if (pending_ret < 0) {
1838 ret = LTTNG_ERR_UNK;
1839 goto setup_error;
1840 } else {
1841 ret = pending_ret;
1842 goto setup_error;
1843 }
1844
1845 pending_ret_byte = (uint8_t) pending_ret;
1846
1847 /* 1 byte to return whether or not data is pending */
1848 ret = setup_lttng_msg_no_cmd_header(cmd_ctx,
1849 &pending_ret_byte, 1);
1850
1851 if (ret < 0) {
1852 goto setup_error;
1853 }
1854
1855 ret = LTTNG_OK;
1856 break;
1857 }
1858 case LTTNG_SNAPSHOT_ADD_OUTPUT:
1859 {
1860 uint32_t snapshot_id;
1861 struct lttcomm_lttng_output_id reply;
1862
1863 ret = cmd_snapshot_add_output(cmd_ctx->session,
1864 ALIGNED_CONST_PTR(cmd_ctx->lsm->u.snapshot_output.output),
1865 &snapshot_id);
1866 if (ret != LTTNG_OK) {
1867 goto error;
1868 }
1869 reply.id = snapshot_id;
1870
1871 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &reply,
1872 sizeof(reply));
1873 if (ret < 0) {
1874 goto setup_error;
1875 }
1876
1877 /* Copy output list into message payload */
1878 ret = LTTNG_OK;
1879 break;
1880 }
1881 case LTTNG_SNAPSHOT_DEL_OUTPUT:
1882 {
1883 ret = cmd_snapshot_del_output(cmd_ctx->session,
1884 ALIGNED_CONST_PTR(cmd_ctx->lsm->u.snapshot_output.output));
1885 break;
1886 }
1887 case LTTNG_SNAPSHOT_LIST_OUTPUT:
1888 {
1889 ssize_t nb_output;
1890 struct lttng_snapshot_output *outputs = NULL;
1891
1892 nb_output = cmd_snapshot_list_outputs(cmd_ctx->session, &outputs);
1893 if (nb_output < 0) {
1894 ret = -nb_output;
1895 goto error;
1896 }
1897
1898 assert((nb_output > 0 && outputs) || nb_output == 0);
1899 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, outputs,
1900 nb_output * sizeof(struct lttng_snapshot_output));
1901 free(outputs);
1902
1903 if (ret < 0) {
1904 goto setup_error;
1905 }
1906
1907 ret = LTTNG_OK;
1908 break;
1909 }
1910 case LTTNG_SNAPSHOT_RECORD:
1911 {
1912 ret = cmd_snapshot_record(cmd_ctx->session,
1913 ALIGNED_CONST_PTR(cmd_ctx->lsm->u.snapshot_record.output),
1914 cmd_ctx->lsm->u.snapshot_record.wait);
1915 break;
1916 }
1917 case LTTNG_CREATE_SESSION_EXT:
1918 {
1919 struct lttng_dynamic_buffer payload;
1920 struct lttng_session_descriptor *return_descriptor = NULL;
1921
1922 lttng_dynamic_buffer_init(&payload);
1923 ret = cmd_create_session(cmd_ctx, *sock, &return_descriptor);
1924 if (ret != LTTNG_OK) {
1925 goto error;
1926 }
1927
1928 ret = lttng_session_descriptor_serialize(return_descriptor,
1929 &payload);
1930 if (ret) {
1931 ERR("Failed to serialize session descriptor in reply to \"create session\" command");
1932 lttng_session_descriptor_destroy(return_descriptor);
1933 ret = LTTNG_ERR_NOMEM;
1934 goto error;
1935 }
1936 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, payload.data,
1937 payload.size);
1938 if (ret) {
1939 lttng_session_descriptor_destroy(return_descriptor);
1940 ret = LTTNG_ERR_NOMEM;
1941 goto error;
1942 }
1943 lttng_dynamic_buffer_reset(&payload);
1944 lttng_session_descriptor_destroy(return_descriptor);
1945 ret = LTTNG_OK;
1946 break;
1947 }
1948 case LTTNG_SAVE_SESSION:
1949 {
1950 ret = cmd_save_sessions(&cmd_ctx->lsm->u.save_session.attr,
1951 &cmd_ctx->creds);
1952 break;
1953 }
1954 case LTTNG_SET_SESSION_SHM_PATH:
1955 {
1956 ret = cmd_set_session_shm_path(cmd_ctx->session,
1957 cmd_ctx->lsm->u.set_shm_path.shm_path);
1958 break;
1959 }
1960 case LTTNG_REGENERATE_METADATA:
1961 {
1962 ret = cmd_regenerate_metadata(cmd_ctx->session);
1963 break;
1964 }
1965 case LTTNG_REGENERATE_STATEDUMP:
1966 {
1967 ret = cmd_regenerate_statedump(cmd_ctx->session);
1968 break;
1969 }
1970 case LTTNG_REGISTER_TRIGGER:
1971 {
1972 ret = cmd_register_trigger(cmd_ctx, *sock,
1973 notification_thread_handle);
1974 break;
1975 }
1976 case LTTNG_UNREGISTER_TRIGGER:
1977 {
1978 ret = cmd_unregister_trigger(cmd_ctx, *sock,
1979 notification_thread_handle);
1980 break;
1981 }
1982 case LTTNG_ROTATE_SESSION:
1983 {
1984 struct lttng_rotate_session_return rotate_return;
1985
1986 DBG("Client rotate session \"%s\"", cmd_ctx->session->name);
1987
1988 memset(&rotate_return, 0, sizeof(rotate_return));
1989 if (cmd_ctx->session->kernel_session && !check_rotate_compatible()) {
1990 DBG("Kernel tracer version is not compatible with the rotation feature");
1991 ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
1992 goto error;
1993 }
1994
1995 ret = cmd_rotate_session(cmd_ctx->session, &rotate_return,
1996 false,
1997 LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED);
1998 if (ret < 0) {
1999 ret = -ret;
2000 goto error;
2001 }
2002
2003 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &rotate_return,
2004 sizeof(rotate_return));
2005 if (ret < 0) {
2006 ret = -ret;
2007 goto error;
2008 }
2009
2010 ret = LTTNG_OK;
2011 break;
2012 }
2013 case LTTNG_ROTATION_GET_INFO:
2014 {
2015 struct lttng_rotation_get_info_return get_info_return;
2016
2017 memset(&get_info_return, 0, sizeof(get_info_return));
2018 ret = cmd_rotate_get_info(cmd_ctx->session, &get_info_return,
2019 cmd_ctx->lsm->u.get_rotation_info.rotation_id);
2020 if (ret < 0) {
2021 ret = -ret;
2022 goto error;
2023 }
2024
2025 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &get_info_return,
2026 sizeof(get_info_return));
2027 if (ret < 0) {
2028 ret = -ret;
2029 goto error;
2030 }
2031
2032 ret = LTTNG_OK;
2033 break;
2034 }
2035 case LTTNG_ROTATION_SET_SCHEDULE:
2036 {
2037 bool set_schedule;
2038 enum lttng_rotation_schedule_type schedule_type;
2039 uint64_t value;
2040
2041 if (cmd_ctx->session->kernel_session && !check_rotate_compatible()) {
2042 DBG("Kernel tracer version does not support session rotations");
2043 ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
2044 goto error;
2045 }
2046
2047 set_schedule = cmd_ctx->lsm->u.rotation_set_schedule.set == 1;
2048 schedule_type = (enum lttng_rotation_schedule_type) cmd_ctx->lsm->u.rotation_set_schedule.type;
2049 value = cmd_ctx->lsm->u.rotation_set_schedule.value;
2050
2051 ret = cmd_rotation_set_schedule(cmd_ctx->session,
2052 set_schedule,
2053 schedule_type,
2054 value,
2055 notification_thread_handle);
2056 if (ret != LTTNG_OK) {
2057 goto error;
2058 }
2059
2060 break;
2061 }
2062 case LTTNG_SESSION_LIST_ROTATION_SCHEDULES:
2063 {
2064 struct lttng_session_list_schedules_return schedules = {
2065 .periodic.set = !!cmd_ctx->session->rotate_timer_period,
2066 .periodic.value = cmd_ctx->session->rotate_timer_period,
2067 .size.set = !!cmd_ctx->session->rotate_size,
2068 .size.value = cmd_ctx->session->rotate_size,
2069 };
2070
2071 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &schedules,
2072 sizeof(schedules));
2073 if (ret < 0) {
2074 ret = -ret;
2075 goto error;
2076 }
2077
2078 ret = LTTNG_OK;
2079 break;
2080 }
2081 case LTTNG_CLEAR_SESSION:
2082 {
2083 ret = cmd_clear_session(cmd_ctx->session, sock);
2084 break;
2085 }
2086 default:
2087 ret = LTTNG_ERR_UND;
2088 break;
2089 }
2090
2091 error:
2092 if (cmd_ctx->llm == NULL) {
2093 DBG("Missing llm structure. Allocating one.");
2094 if (setup_lttng_msg_no_cmd_header(cmd_ctx, NULL, 0) < 0) {
2095 goto setup_error;
2096 }
2097 }
2098 /* Set return code */
2099 cmd_ctx->llm->ret_code = ret;
2100 setup_error:
2101 if (cmd_ctx->session) {
2102 session_unlock(cmd_ctx->session);
2103 session_put(cmd_ctx->session);
2104 cmd_ctx->session = NULL;
2105 }
2106 if (need_tracing_session) {
2107 session_unlock_list();
2108 }
2109 init_setup_error:
2110 assert(!rcu_read_ongoing());
2111 return ret;
2112 }
2113
2114 static int create_client_sock(void)
2115 {
2116 int ret, client_sock;
2117 const mode_t old_umask = umask(0);
2118
2119 /* Create client tool unix socket */
2120 client_sock = lttcomm_create_unix_sock(config.client_unix_sock_path.value);
2121 if (client_sock < 0) {
2122 ERR("Create unix sock failed: %s", config.client_unix_sock_path.value);
2123 ret = -1;
2124 goto end;
2125 }
2126
2127 /* Set the cloexec flag */
2128 ret = utils_set_fd_cloexec(client_sock);
2129 if (ret < 0) {
2130 ERR("Unable to set CLOEXEC flag to the client Unix socket (fd: %d). "
2131 "Continuing but note that the consumer daemon will have a "
2132 "reference to this socket on exec()", client_sock);
2133 }
2134
2135 /* File permission MUST be 660 */
2136 ret = chmod(config.client_unix_sock_path.value, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
2137 if (ret < 0) {
2138 ERR("Set file permissions failed: %s",
2139 config.client_unix_sock_path.value);
2140 PERROR("chmod");
2141 (void) lttcomm_close_unix_sock(client_sock);
2142 ret = -1;
2143 goto end;
2144 }
2145 DBG("Created client socket (fd = %i)", client_sock);
2146 ret = client_sock;
2147 end:
2148 umask(old_umask);
2149 return ret;
2150 }
2151
2152 static void cleanup_client_thread(void *data)
2153 {
2154 struct lttng_pipe *quit_pipe = data;
2155
2156 lttng_pipe_destroy(quit_pipe);
2157 }
2158
2159 static void thread_init_cleanup(void *data)
2160 {
2161 set_thread_status(false);
2162 }
2163
2164 /*
2165 * This thread manage all clients request using the unix client socket for
2166 * communication.
2167 */
2168 static void *thread_manage_clients(void *data)
2169 {
2170 int sock = -1, ret, i, pollfd, err = -1;
2171 int sock_error;
2172 uint32_t revents, nb_fd;
2173 struct command_ctx *cmd_ctx = NULL;
2174 struct lttng_poll_event events;
2175 const int client_sock = thread_state.client_sock;
2176 struct lttng_pipe *quit_pipe = data;
2177 const int thread_quit_pipe_fd = lttng_pipe_get_readfd(quit_pipe);
2178
2179 DBG("[thread] Manage client started");
2180
2181 is_root = (getuid() == 0);
2182
2183 pthread_cleanup_push(thread_init_cleanup, NULL);
2184
2185 rcu_register_thread();
2186
2187 health_register(health_sessiond, HEALTH_SESSIOND_TYPE_CMD);
2188
2189 health_code_update();
2190
2191 ret = lttcomm_listen_unix_sock(client_sock);
2192 if (ret < 0) {
2193 goto error_listen;
2194 }
2195
2196 /*
2197 * Pass 2 as size here for the thread quit pipe and client_sock. Nothing
2198 * more will be added to this poll set.
2199 */
2200 ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
2201 if (ret < 0) {
2202 goto error_create_poll;
2203 }
2204
2205 /* Add the application registration socket */
2206 ret = lttng_poll_add(&events, client_sock, LPOLLIN | LPOLLPRI);
2207 if (ret < 0) {
2208 goto error;
2209 }
2210
2211 /* Add thread quit pipe */
2212 ret = lttng_poll_add(&events, thread_quit_pipe_fd, LPOLLIN | LPOLLERR);
2213 if (ret < 0) {
2214 goto error;
2215 }
2216
2217 /* Set state as running. */
2218 set_thread_status(true);
2219 pthread_cleanup_pop(0);
2220
2221 /* This testpoint is after we signal readiness to the parent. */
2222 if (testpoint(sessiond_thread_manage_clients)) {
2223 goto error;
2224 }
2225
2226 if (testpoint(sessiond_thread_manage_clients_before_loop)) {
2227 goto error;
2228 }
2229
2230 health_code_update();
2231
2232 while (1) {
2233 const struct cmd_completion_handler *cmd_completion_handler;
2234
2235 DBG("Accepting client command ...");
2236
2237 /* Inifinite blocking call, waiting for transmission */
2238 restart:
2239 health_poll_entry();
2240 ret = lttng_poll_wait(&events, -1);
2241 health_poll_exit();
2242 if (ret < 0) {
2243 /*
2244 * Restart interrupted system call.
2245 */
2246 if (errno == EINTR) {
2247 goto restart;
2248 }
2249 goto error;
2250 }
2251
2252 nb_fd = ret;
2253
2254 for (i = 0; i < nb_fd; i++) {
2255 revents = LTTNG_POLL_GETEV(&events, i);
2256 pollfd = LTTNG_POLL_GETFD(&events, i);
2257
2258 health_code_update();
2259
2260 if (pollfd == thread_quit_pipe_fd) {
2261 err = 0;
2262 goto exit;
2263 } else {
2264 /* Event on the registration socket */
2265 if (revents & LPOLLIN) {
2266 continue;
2267 } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
2268 ERR("Client socket poll error");
2269 goto error;
2270 } else {
2271 ERR("Unexpected poll events %u for sock %d", revents, pollfd);
2272 goto error;
2273 }
2274 }
2275 }
2276
2277 DBG("Wait for client response");
2278
2279 health_code_update();
2280
2281 sock = lttcomm_accept_unix_sock(client_sock);
2282 if (sock < 0) {
2283 goto error;
2284 }
2285
2286 /*
2287 * Set the CLOEXEC flag. Return code is useless because either way, the
2288 * show must go on.
2289 */
2290 (void) utils_set_fd_cloexec(sock);
2291
2292 /* Set socket option for credentials retrieval */
2293 ret = lttcomm_setsockopt_creds_unix_sock(sock);
2294 if (ret < 0) {
2295 goto error;
2296 }
2297
2298 /* Allocate context command to process the client request */
2299 cmd_ctx = zmalloc(sizeof(struct command_ctx));
2300 if (cmd_ctx == NULL) {
2301 PERROR("zmalloc cmd_ctx");
2302 goto error;
2303 }
2304
2305 /* Allocate data buffer for reception */
2306 cmd_ctx->lsm = zmalloc(sizeof(struct lttcomm_session_msg));
2307 if (cmd_ctx->lsm == NULL) {
2308 PERROR("zmalloc cmd_ctx->lsm");
2309 goto error;
2310 }
2311
2312 cmd_ctx->llm = NULL;
2313 cmd_ctx->session = NULL;
2314
2315 health_code_update();
2316
2317 /*
2318 * Data is received from the lttng client. The struct
2319 * lttcomm_session_msg (lsm) contains the command and data request of
2320 * the client.
2321 */
2322 DBG("Receiving data from client ...");
2323 ret = lttcomm_recv_creds_unix_sock(sock, cmd_ctx->lsm,
2324 sizeof(struct lttcomm_session_msg), &cmd_ctx->creds);
2325 if (ret <= 0) {
2326 DBG("Nothing recv() from client... continuing");
2327 ret = close(sock);
2328 if (ret) {
2329 PERROR("close");
2330 }
2331 sock = -1;
2332 clean_command_ctx(&cmd_ctx);
2333 continue;
2334 }
2335
2336 health_code_update();
2337
2338 // TODO: Validate cmd_ctx including sanity check for
2339 // security purpose.
2340
2341 rcu_thread_online();
2342 /*
2343 * This function dispatch the work to the kernel or userspace tracer
2344 * libs and fill the lttcomm_lttng_msg data structure of all the needed
2345 * informations for the client. The command context struct contains
2346 * everything this function may needs.
2347 */
2348 ret = process_client_msg(cmd_ctx, &sock, &sock_error);
2349 rcu_thread_offline();
2350 if (ret < 0) {
2351 if (sock >= 0) {
2352 ret = close(sock);
2353 if (ret) {
2354 PERROR("close");
2355 }
2356 }
2357 sock = -1;
2358 /*
2359 * TODO: Inform client somehow of the fatal error. At
2360 * this point, ret < 0 means that a zmalloc failed
2361 * (ENOMEM). Error detected but still accept
2362 * command, unless a socket error has been
2363 * detected.
2364 */
2365 clean_command_ctx(&cmd_ctx);
2366 continue;
2367 }
2368
2369 cmd_completion_handler = cmd_pop_completion_handler();
2370 if (cmd_completion_handler) {
2371 enum lttng_error_code completion_code;
2372
2373 completion_code = cmd_completion_handler->run(
2374 cmd_completion_handler->data);
2375 if (completion_code != LTTNG_OK) {
2376 clean_command_ctx(&cmd_ctx);
2377 continue;
2378 }
2379 }
2380
2381 health_code_update();
2382
2383 if (sock >= 0) {
2384 DBG("Sending response (size: %d, retcode: %s (%d))",
2385 cmd_ctx->lttng_msg_size,
2386 lttng_strerror(-cmd_ctx->llm->ret_code),
2387 cmd_ctx->llm->ret_code);
2388 ret = send_unix_sock(sock, cmd_ctx->llm,
2389 cmd_ctx->lttng_msg_size);
2390 if (ret < 0) {
2391 ERR("Failed to send data back to client");
2392 }
2393
2394 /* End of transmission */
2395 ret = close(sock);
2396 if (ret) {
2397 PERROR("close");
2398 }
2399 }
2400 sock = -1;
2401
2402 clean_command_ctx(&cmd_ctx);
2403
2404 health_code_update();
2405 }
2406
2407 exit:
2408 error:
2409 if (sock >= 0) {
2410 ret = close(sock);
2411 if (ret) {
2412 PERROR("close");
2413 }
2414 }
2415
2416 lttng_poll_clean(&events);
2417 clean_command_ctx(&cmd_ctx);
2418
2419 error_listen:
2420 error_create_poll:
2421 unlink(config.client_unix_sock_path.value);
2422 ret = close(client_sock);
2423 if (ret) {
2424 PERROR("close");
2425 }
2426
2427 if (err) {
2428 health_error();
2429 ERR("Health error occurred in %s", __func__);
2430 }
2431
2432 health_unregister(health_sessiond);
2433
2434 DBG("Client thread dying");
2435
2436 rcu_unregister_thread();
2437 return NULL;
2438 }
2439
2440 static
2441 bool shutdown_client_thread(void *thread_data)
2442 {
2443 struct lttng_pipe *client_quit_pipe = thread_data;
2444 const int write_fd = lttng_pipe_get_writefd(client_quit_pipe);
2445
2446 return notify_thread_pipe(write_fd) == 1;
2447 }
2448
2449 struct lttng_thread *launch_client_thread(void)
2450 {
2451 bool thread_running;
2452 struct lttng_pipe *client_quit_pipe;
2453 struct lttng_thread *thread = NULL;
2454 int client_sock_fd = -1;
2455
2456 sem_init(&thread_state.ready, 0, 0);
2457 client_quit_pipe = lttng_pipe_open(FD_CLOEXEC);
2458 if (!client_quit_pipe) {
2459 goto error;
2460 }
2461
2462 client_sock_fd = create_client_sock();
2463 if (client_sock_fd < 0) {
2464 goto error;
2465 }
2466
2467 thread_state.client_sock = client_sock_fd;
2468 thread = lttng_thread_create("Client management",
2469 thread_manage_clients,
2470 shutdown_client_thread,
2471 cleanup_client_thread,
2472 client_quit_pipe);
2473 if (!thread) {
2474 goto error;
2475 }
2476 /* The client thread now owns the client sock fd and the quit pipe. */
2477 client_sock_fd = -1;
2478 client_quit_pipe = NULL;
2479
2480 /*
2481 * This thread is part of the threads that need to be fully
2482 * initialized before the session daemon is marked as "ready".
2483 */
2484 thread_running = wait_thread_status();
2485 if (!thread_running) {
2486 goto error;
2487 }
2488 return thread;
2489 error:
2490 if (client_sock_fd >= 0) {
2491 if (close(client_sock_fd)) {
2492 PERROR("Failed to close client socket");
2493 }
2494 }
2495 lttng_thread_put(thread);
2496 cleanup_client_thread(client_quit_pipe);
2497 return NULL;
2498 }
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