a36b81c18a127b536f0a11abf5d48ccc2fafe4be
[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
499 return LTTNG_OK;
500
501 error:
502 trace_kernel_destroy_session(session->kernel_session);
503 session->kernel_session = NULL;
504 error_create:
505 return ret;
506 }
507
508 /*
509 * Count number of session permitted by uid/gid.
510 */
511 static unsigned int lttng_sessions_count(uid_t uid, gid_t gid)
512 {
513 unsigned int i = 0;
514 struct ltt_session *session;
515 const struct ltt_session_list *session_list = session_get_list();
516
517 DBG("Counting number of available session for UID %d GID %d",
518 uid, gid);
519 cds_list_for_each_entry(session, &session_list->head, list) {
520 if (!session_get(session)) {
521 continue;
522 }
523 session_lock(session);
524 /* Only count the sessions the user can control. */
525 if (session_access_ok(session, uid, gid) &&
526 !session->destroyed) {
527 i++;
528 }
529 session_unlock(session);
530 session_put(session);
531 }
532 return i;
533 }
534
535 static int receive_userspace_probe(struct command_ctx *cmd_ctx, int sock,
536 int *sock_error, struct lttng_event *event)
537 {
538 int fd, ret;
539 struct lttng_userspace_probe_location *probe_location;
540 const struct lttng_userspace_probe_location_lookup_method *lookup = NULL;
541 struct lttng_dynamic_buffer probe_location_buffer;
542 struct lttng_buffer_view buffer_view;
543
544 /*
545 * Create a buffer to store the serialized version of the probe
546 * location.
547 */
548 lttng_dynamic_buffer_init(&probe_location_buffer);
549 ret = lttng_dynamic_buffer_set_size(&probe_location_buffer,
550 cmd_ctx->lsm->u.enable.userspace_probe_location_len);
551 if (ret) {
552 ret = LTTNG_ERR_NOMEM;
553 goto error;
554 }
555
556 /*
557 * Receive the probe location.
558 */
559 ret = lttcomm_recv_unix_sock(sock, probe_location_buffer.data,
560 probe_location_buffer.size);
561 if (ret <= 0) {
562 DBG("Nothing recv() from client var len data... continuing");
563 *sock_error = 1;
564 lttng_dynamic_buffer_reset(&probe_location_buffer);
565 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
566 goto error;
567 }
568
569 buffer_view = lttng_buffer_view_from_dynamic_buffer(
570 &probe_location_buffer, 0, probe_location_buffer.size);
571
572 /*
573 * Extract the probe location from the serialized version.
574 */
575 ret = lttng_userspace_probe_location_create_from_buffer(
576 &buffer_view, &probe_location);
577 if (ret < 0) {
578 WARN("Failed to create a userspace probe location from the received buffer");
579 lttng_dynamic_buffer_reset( &probe_location_buffer);
580 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
581 goto error;
582 }
583
584 /*
585 * Receive the file descriptor to the target binary from the client.
586 */
587 DBG("Receiving userspace probe target FD from client ...");
588 ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1);
589 if (ret <= 0) {
590 DBG("Nothing recv() from client userspace probe fd... continuing");
591 *sock_error = 1;
592 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
593 goto error;
594 }
595
596 /*
597 * Set the file descriptor received from the client through the unix
598 * socket in the probe location.
599 */
600 lookup = lttng_userspace_probe_location_get_lookup_method(probe_location);
601 if (!lookup) {
602 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
603 goto error;
604 }
605
606 /*
607 * From the kernel tracer's perspective, all userspace probe event types
608 * are all the same: a file and an offset.
609 */
610 switch (lttng_userspace_probe_location_lookup_method_get_type(lookup)) {
611 case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF:
612 ret = lttng_userspace_probe_location_function_set_binary_fd(
613 probe_location, fd);
614 break;
615 case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT:
616 ret = lttng_userspace_probe_location_tracepoint_set_binary_fd(
617 probe_location, fd);
618 break;
619 default:
620 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
621 goto error;
622 }
623
624 if (ret) {
625 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
626 goto error;
627 }
628
629 /* Attach the probe location to the event. */
630 ret = lttng_event_set_userspace_probe_location(event, probe_location);
631 if (ret) {
632 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
633 goto error;
634 }
635
636 lttng_dynamic_buffer_reset(&probe_location_buffer);
637 error:
638 return ret;
639 }
640
641 /*
642 * Version of setup_lttng_msg() without command header.
643 */
644 static int setup_lttng_msg_no_cmd_header(struct command_ctx *cmd_ctx,
645 void *payload_buf, size_t payload_len)
646 {
647 return setup_lttng_msg(cmd_ctx, payload_buf, payload_len, NULL, 0);
648 }
649
650 /*
651 * Free memory of a command context structure.
652 */
653 static void clean_command_ctx(struct command_ctx **cmd_ctx)
654 {
655 DBG("Clean command context structure");
656 if (*cmd_ctx) {
657 if ((*cmd_ctx)->llm) {
658 free((*cmd_ctx)->llm);
659 }
660 if ((*cmd_ctx)->lsm) {
661 free((*cmd_ctx)->lsm);
662 }
663 free(*cmd_ctx);
664 *cmd_ctx = NULL;
665 }
666 }
667
668 /*
669 * Check if the current kernel tracer supports the session rotation feature.
670 * Return 1 if it does, 0 otherwise.
671 */
672 static int check_rotate_compatible(void)
673 {
674 int ret = 1;
675
676 if (kernel_tracer_version.major != 2 || kernel_tracer_version.minor < 11) {
677 DBG("Kernel tracer version is not compatible with the rotation feature");
678 ret = 0;
679 }
680
681 return ret;
682 }
683
684 /*
685 * Send data on a unix socket using the liblttsessiondcomm API.
686 *
687 * Return lttcomm error code.
688 */
689 static int send_unix_sock(int sock, void *buf, size_t len)
690 {
691 /* Check valid length */
692 if (len == 0) {
693 return -1;
694 }
695
696 return lttcomm_send_unix_sock(sock, buf, len);
697 }
698
699 /*
700 * Process the command requested by the lttng client within the command
701 * context structure. This function make sure that the return structure (llm)
702 * is set and ready for transmission before returning.
703 *
704 * Return any error encountered or 0 for success.
705 *
706 * "sock" is only used for special-case var. len data.
707 * A command may assume the ownership of the socket, in which case its value
708 * should be set to -1.
709 *
710 * Should *NOT* be called with RCU read-side lock held.
711 */
712 static int process_client_msg(struct command_ctx *cmd_ctx, int *sock,
713 int *sock_error)
714 {
715 int ret = LTTNG_OK;
716 int need_tracing_session = 1;
717 int need_domain;
718
719 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
720
721 assert(!rcu_read_ongoing());
722
723 *sock_error = 0;
724
725 switch (cmd_ctx->lsm->cmd_type) {
726 case LTTNG_CREATE_SESSION_EXT:
727 case LTTNG_DESTROY_SESSION:
728 case LTTNG_LIST_SESSIONS:
729 case LTTNG_LIST_DOMAINS:
730 case LTTNG_START_TRACE:
731 case LTTNG_STOP_TRACE:
732 case LTTNG_DATA_PENDING:
733 case LTTNG_SNAPSHOT_ADD_OUTPUT:
734 case LTTNG_SNAPSHOT_DEL_OUTPUT:
735 case LTTNG_SNAPSHOT_LIST_OUTPUT:
736 case LTTNG_SNAPSHOT_RECORD:
737 case LTTNG_SAVE_SESSION:
738 case LTTNG_SET_SESSION_SHM_PATH:
739 case LTTNG_REGENERATE_METADATA:
740 case LTTNG_REGENERATE_STATEDUMP:
741 case LTTNG_REGISTER_TRIGGER:
742 case LTTNG_UNREGISTER_TRIGGER:
743 case LTTNG_ROTATE_SESSION:
744 case LTTNG_ROTATION_GET_INFO:
745 case LTTNG_ROTATION_SET_SCHEDULE:
746 case LTTNG_SESSION_LIST_ROTATION_SCHEDULES:
747 case LTTNG_CLEAR_SESSION:
748 need_domain = 0;
749 break;
750 default:
751 need_domain = 1;
752 }
753
754 if (config.no_kernel && need_domain
755 && cmd_ctx->lsm->domain.type == LTTNG_DOMAIN_KERNEL) {
756 if (!is_root) {
757 ret = LTTNG_ERR_NEED_ROOT_SESSIOND;
758 } else {
759 ret = LTTNG_ERR_KERN_NA;
760 }
761 goto error;
762 }
763
764 /* Deny register consumer if we already have a spawned consumer. */
765 if (cmd_ctx->lsm->cmd_type == LTTNG_REGISTER_CONSUMER) {
766 pthread_mutex_lock(&kconsumer_data.pid_mutex);
767 if (kconsumer_data.pid > 0) {
768 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
769 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
770 goto error;
771 }
772 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
773 }
774
775 /*
776 * Check for command that don't needs to allocate a returned payload. We do
777 * this here so we don't have to make the call for no payload at each
778 * command.
779 */
780 switch(cmd_ctx->lsm->cmd_type) {
781 case LTTNG_LIST_SESSIONS:
782 case LTTNG_LIST_TRACEPOINTS:
783 case LTTNG_LIST_TRACEPOINT_FIELDS:
784 case LTTNG_LIST_DOMAINS:
785 case LTTNG_LIST_CHANNELS:
786 case LTTNG_LIST_EVENTS:
787 case LTTNG_LIST_SYSCALLS:
788 case LTTNG_SESSION_LIST_ROTATION_SCHEDULES:
789 case LTTNG_PROCESS_ATTR_TRACKER_GET_POLICY:
790 case LTTNG_PROCESS_ATTR_TRACKER_GET_INCLUSION_SET:
791 case LTTNG_DATA_PENDING:
792 case LTTNG_ROTATE_SESSION:
793 case LTTNG_ROTATION_GET_INFO:
794 break;
795 default:
796 /* Setup lttng message with no payload */
797 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, NULL, 0);
798 if (ret < 0) {
799 /* This label does not try to unlock the session */
800 goto init_setup_error;
801 }
802 }
803
804 /* Commands that DO NOT need a session. */
805 switch (cmd_ctx->lsm->cmd_type) {
806 case LTTNG_CREATE_SESSION_EXT:
807 case LTTNG_LIST_SESSIONS:
808 case LTTNG_LIST_TRACEPOINTS:
809 case LTTNG_LIST_SYSCALLS:
810 case LTTNG_LIST_TRACEPOINT_FIELDS:
811 case LTTNG_SAVE_SESSION:
812 case LTTNG_REGISTER_TRIGGER:
813 case LTTNG_UNREGISTER_TRIGGER:
814 need_tracing_session = 0;
815 break;
816 default:
817 DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
818 /*
819 * We keep the session list lock across _all_ commands
820 * for now, because the per-session lock does not
821 * handle teardown properly.
822 */
823 session_lock_list();
824 cmd_ctx->session = session_find_by_name(cmd_ctx->lsm->session.name);
825 if (cmd_ctx->session == NULL) {
826 ret = LTTNG_ERR_SESS_NOT_FOUND;
827 goto error;
828 } else {
829 /* Acquire lock for the session */
830 session_lock(cmd_ctx->session);
831 }
832 break;
833 }
834
835 /*
836 * Commands that need a valid session but should NOT create one if none
837 * exists. Instead of creating one and destroying it when the command is
838 * handled, process that right before so we save some round trip in useless
839 * code path.
840 */
841 switch (cmd_ctx->lsm->cmd_type) {
842 case LTTNG_DISABLE_CHANNEL:
843 case LTTNG_DISABLE_EVENT:
844 switch (cmd_ctx->lsm->domain.type) {
845 case LTTNG_DOMAIN_KERNEL:
846 if (!cmd_ctx->session->kernel_session) {
847 ret = LTTNG_ERR_NO_CHANNEL;
848 goto error;
849 }
850 break;
851 case LTTNG_DOMAIN_JUL:
852 case LTTNG_DOMAIN_LOG4J:
853 case LTTNG_DOMAIN_PYTHON:
854 case LTTNG_DOMAIN_UST:
855 if (!cmd_ctx->session->ust_session) {
856 ret = LTTNG_ERR_NO_CHANNEL;
857 goto error;
858 }
859 break;
860 default:
861 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
862 goto error;
863 }
864 default:
865 break;
866 }
867
868 if (!need_domain) {
869 goto skip_domain;
870 }
871
872 /*
873 * Check domain type for specific "pre-action".
874 */
875 switch (cmd_ctx->lsm->domain.type) {
876 case LTTNG_DOMAIN_KERNEL:
877 if (!is_root) {
878 ret = LTTNG_ERR_NEED_ROOT_SESSIOND;
879 goto error;
880 }
881
882 /* Kernel tracer check */
883 if (!kernel_tracer_is_initialized()) {
884 /* Basically, load kernel tracer modules */
885 ret = init_kernel_tracer();
886 if (ret != 0) {
887 goto error;
888 }
889 }
890
891 /* Consumer is in an ERROR state. Report back to client */
892 if (uatomic_read(&kernel_consumerd_state) == CONSUMER_ERROR) {
893 ret = LTTNG_ERR_NO_KERNCONSUMERD;
894 goto error;
895 }
896
897 /* Need a session for kernel command */
898 if (need_tracing_session) {
899 if (cmd_ctx->session->kernel_session == NULL) {
900 ret = create_kernel_session(cmd_ctx->session);
901 if (ret != LTTNG_OK) {
902 ret = LTTNG_ERR_KERN_SESS_FAIL;
903 goto error;
904 }
905 }
906
907 /* Start the kernel consumer daemon */
908 pthread_mutex_lock(&kconsumer_data.pid_mutex);
909 if (kconsumer_data.pid == 0 &&
910 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
911 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
912 ret = start_consumerd(&kconsumer_data);
913 if (ret < 0) {
914 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
915 goto error;
916 }
917 uatomic_set(&kernel_consumerd_state, CONSUMER_STARTED);
918 } else {
919 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
920 }
921
922 /*
923 * The consumer was just spawned so we need to add the socket to
924 * the consumer output of the session if exist.
925 */
926 ret = consumer_create_socket(&kconsumer_data,
927 cmd_ctx->session->kernel_session->consumer);
928 if (ret < 0) {
929 goto error;
930 }
931 }
932
933 break;
934 case LTTNG_DOMAIN_JUL:
935 case LTTNG_DOMAIN_LOG4J:
936 case LTTNG_DOMAIN_PYTHON:
937 case LTTNG_DOMAIN_UST:
938 {
939 if (!ust_app_supported()) {
940 ret = LTTNG_ERR_NO_UST;
941 goto error;
942 }
943 /* Consumer is in an ERROR state. Report back to client */
944 if (uatomic_read(&ust_consumerd_state) == CONSUMER_ERROR) {
945 ret = LTTNG_ERR_NO_USTCONSUMERD;
946 goto error;
947 }
948
949 if (need_tracing_session) {
950 /* Create UST session if none exist. */
951 if (cmd_ctx->session->ust_session == NULL) {
952 ret = create_ust_session(cmd_ctx->session,
953 ALIGNED_CONST_PTR(cmd_ctx->lsm->domain));
954 if (ret != LTTNG_OK) {
955 goto error;
956 }
957 }
958
959 /* Start the UST consumer daemons */
960 /* 64-bit */
961 pthread_mutex_lock(&ustconsumer64_data.pid_mutex);
962 if (config.consumerd64_bin_path.value &&
963 ustconsumer64_data.pid == 0 &&
964 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
965 pthread_mutex_unlock(&ustconsumer64_data.pid_mutex);
966 ret = start_consumerd(&ustconsumer64_data);
967 if (ret < 0) {
968 ret = LTTNG_ERR_UST_CONSUMER64_FAIL;
969 uatomic_set(&ust_consumerd64_fd, -EINVAL);
970 goto error;
971 }
972
973 uatomic_set(&ust_consumerd64_fd, ustconsumer64_data.cmd_sock);
974 uatomic_set(&ust_consumerd_state, CONSUMER_STARTED);
975 } else {
976 pthread_mutex_unlock(&ustconsumer64_data.pid_mutex);
977 }
978
979 /*
980 * Setup socket for consumer 64 bit. No need for atomic access
981 * since it was set above and can ONLY be set in this thread.
982 */
983 ret = consumer_create_socket(&ustconsumer64_data,
984 cmd_ctx->session->ust_session->consumer);
985 if (ret < 0) {
986 goto error;
987 }
988
989 /* 32-bit */
990 pthread_mutex_lock(&ustconsumer32_data.pid_mutex);
991 if (config.consumerd32_bin_path.value &&
992 ustconsumer32_data.pid == 0 &&
993 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
994 pthread_mutex_unlock(&ustconsumer32_data.pid_mutex);
995 ret = start_consumerd(&ustconsumer32_data);
996 if (ret < 0) {
997 ret = LTTNG_ERR_UST_CONSUMER32_FAIL;
998 uatomic_set(&ust_consumerd32_fd, -EINVAL);
999 goto error;
1000 }
1001
1002 uatomic_set(&ust_consumerd32_fd, ustconsumer32_data.cmd_sock);
1003 uatomic_set(&ust_consumerd_state, CONSUMER_STARTED);
1004 } else {
1005 pthread_mutex_unlock(&ustconsumer32_data.pid_mutex);
1006 }
1007
1008 /*
1009 * Setup socket for consumer 32 bit. No need for atomic access
1010 * since it was set above and can ONLY be set in this thread.
1011 */
1012 ret = consumer_create_socket(&ustconsumer32_data,
1013 cmd_ctx->session->ust_session->consumer);
1014 if (ret < 0) {
1015 goto error;
1016 }
1017 }
1018 break;
1019 }
1020 default:
1021 break;
1022 }
1023 skip_domain:
1024
1025 /* Validate consumer daemon state when start/stop trace command */
1026 if (cmd_ctx->lsm->cmd_type == LTTNG_START_TRACE ||
1027 cmd_ctx->lsm->cmd_type == LTTNG_STOP_TRACE) {
1028 switch (cmd_ctx->lsm->domain.type) {
1029 case LTTNG_DOMAIN_NONE:
1030 break;
1031 case LTTNG_DOMAIN_JUL:
1032 case LTTNG_DOMAIN_LOG4J:
1033 case LTTNG_DOMAIN_PYTHON:
1034 case LTTNG_DOMAIN_UST:
1035 if (uatomic_read(&ust_consumerd_state) != CONSUMER_STARTED) {
1036 ret = LTTNG_ERR_NO_USTCONSUMERD;
1037 goto error;
1038 }
1039 break;
1040 case LTTNG_DOMAIN_KERNEL:
1041 if (uatomic_read(&kernel_consumerd_state) != CONSUMER_STARTED) {
1042 ret = LTTNG_ERR_NO_KERNCONSUMERD;
1043 goto error;
1044 }
1045 break;
1046 default:
1047 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1048 goto error;
1049 }
1050 }
1051
1052 /*
1053 * Check that the UID or GID match that of the tracing session.
1054 * The root user can interact with all sessions.
1055 */
1056 if (need_tracing_session) {
1057 if (!session_access_ok(cmd_ctx->session,
1058 LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
1059 LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds)) ||
1060 cmd_ctx->session->destroyed) {
1061 ret = LTTNG_ERR_EPERM;
1062 goto error;
1063 }
1064 }
1065
1066 /*
1067 * Send relayd information to consumer as soon as we have a domain and a
1068 * session defined.
1069 */
1070 if (cmd_ctx->session && need_domain) {
1071 /*
1072 * Setup relayd if not done yet. If the relayd information was already
1073 * sent to the consumer, this call will gracefully return.
1074 */
1075 ret = cmd_setup_relayd(cmd_ctx->session);
1076 if (ret != LTTNG_OK) {
1077 goto error;
1078 }
1079 }
1080
1081 /* Process by command type */
1082 switch (cmd_ctx->lsm->cmd_type) {
1083 case LTTNG_ADD_CONTEXT:
1084 {
1085 /*
1086 * An LTTNG_ADD_CONTEXT command might have a supplementary
1087 * payload if the context being added is an application context.
1088 */
1089 if (cmd_ctx->lsm->u.context.ctx.ctx ==
1090 LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
1091 char *provider_name = NULL, *context_name = NULL;
1092 size_t provider_name_len =
1093 cmd_ctx->lsm->u.context.provider_name_len;
1094 size_t context_name_len =
1095 cmd_ctx->lsm->u.context.context_name_len;
1096
1097 if (provider_name_len == 0 || context_name_len == 0) {
1098 /*
1099 * Application provider and context names MUST
1100 * be provided.
1101 */
1102 ret = -LTTNG_ERR_INVALID;
1103 goto error;
1104 }
1105
1106 provider_name = zmalloc(provider_name_len + 1);
1107 if (!provider_name) {
1108 ret = -LTTNG_ERR_NOMEM;
1109 goto error;
1110 }
1111 cmd_ctx->lsm->u.context.ctx.u.app_ctx.provider_name =
1112 provider_name;
1113
1114 context_name = zmalloc(context_name_len + 1);
1115 if (!context_name) {
1116 ret = -LTTNG_ERR_NOMEM;
1117 goto error_add_context;
1118 }
1119 cmd_ctx->lsm->u.context.ctx.u.app_ctx.ctx_name =
1120 context_name;
1121
1122 ret = lttcomm_recv_unix_sock(*sock, provider_name,
1123 provider_name_len);
1124 if (ret < 0) {
1125 goto error_add_context;
1126 }
1127
1128 ret = lttcomm_recv_unix_sock(*sock, context_name,
1129 context_name_len);
1130 if (ret < 0) {
1131 goto error_add_context;
1132 }
1133 }
1134
1135 /*
1136 * cmd_add_context assumes ownership of the provider and context
1137 * names.
1138 */
1139 ret = cmd_add_context(cmd_ctx->session,
1140 cmd_ctx->lsm->domain.type,
1141 cmd_ctx->lsm->u.context.channel_name,
1142 ALIGNED_CONST_PTR(cmd_ctx->lsm->u.context.ctx),
1143 kernel_poll_pipe[1]);
1144
1145 cmd_ctx->lsm->u.context.ctx.u.app_ctx.provider_name = NULL;
1146 cmd_ctx->lsm->u.context.ctx.u.app_ctx.ctx_name = NULL;
1147 error_add_context:
1148 free(cmd_ctx->lsm->u.context.ctx.u.app_ctx.provider_name);
1149 free(cmd_ctx->lsm->u.context.ctx.u.app_ctx.ctx_name);
1150 if (ret < 0) {
1151 goto error;
1152 }
1153 break;
1154 }
1155 case LTTNG_DISABLE_CHANNEL:
1156 {
1157 ret = cmd_disable_channel(cmd_ctx->session, cmd_ctx->lsm->domain.type,
1158 cmd_ctx->lsm->u.disable.channel_name);
1159 break;
1160 }
1161 case LTTNG_DISABLE_EVENT:
1162 {
1163
1164 /*
1165 * FIXME: handle filter; for now we just receive the filter's
1166 * bytecode along with the filter expression which are sent by
1167 * liblttng-ctl and discard them.
1168 *
1169 * This fixes an issue where the client may block while sending
1170 * the filter payload and encounter an error because the session
1171 * daemon closes the socket without ever handling this data.
1172 */
1173 size_t count = cmd_ctx->lsm->u.disable.expression_len +
1174 cmd_ctx->lsm->u.disable.bytecode_len;
1175
1176 if (count) {
1177 char data[LTTNG_FILTER_MAX_LEN];
1178
1179 DBG("Discarding disable event command payload of size %zu", count);
1180 while (count) {
1181 ret = lttcomm_recv_unix_sock(*sock, data,
1182 count > sizeof(data) ? sizeof(data) : count);
1183 if (ret < 0) {
1184 goto error;
1185 }
1186
1187 count -= (size_t) ret;
1188 }
1189 }
1190 ret = cmd_disable_event(cmd_ctx->session, cmd_ctx->lsm->domain.type,
1191 cmd_ctx->lsm->u.disable.channel_name,
1192 ALIGNED_CONST_PTR(cmd_ctx->lsm->u.disable.event));
1193 break;
1194 }
1195 case LTTNG_ENABLE_CHANNEL:
1196 {
1197 cmd_ctx->lsm->u.channel.chan.attr.extended.ptr =
1198 (struct lttng_channel_extended *) &cmd_ctx->lsm->u.channel.extended;
1199 ret = cmd_enable_channel(cmd_ctx->session,
1200 ALIGNED_CONST_PTR(cmd_ctx->lsm->domain),
1201 ALIGNED_CONST_PTR(cmd_ctx->lsm->u.channel.chan),
1202 kernel_poll_pipe[1]);
1203 break;
1204 }
1205 case LTTNG_PROCESS_ATTR_TRACKER_ADD_INCLUDE_VALUE:
1206 case LTTNG_PROCESS_ATTR_TRACKER_REMOVE_INCLUDE_VALUE:
1207 {
1208 struct lttng_dynamic_buffer payload;
1209 struct lttng_buffer_view payload_view;
1210 const bool add_value =
1211 cmd_ctx->lsm->cmd_type ==
1212 LTTNG_PROCESS_ATTR_TRACKER_ADD_INCLUDE_VALUE;
1213 const size_t name_len =
1214 cmd_ctx->lsm->u.process_attr_tracker_add_remove_include_value
1215 .name_len;
1216 const enum lttng_domain_type domain_type =
1217 (enum lttng_domain_type)
1218 cmd_ctx->lsm->domain.type;
1219 const enum lttng_process_attr process_attr =
1220 (enum lttng_process_attr) cmd_ctx->lsm->u
1221 .process_attr_tracker_add_remove_include_value
1222 .process_attr;
1223 const enum lttng_process_attr_value_type value_type =
1224 (enum lttng_process_attr_value_type) cmd_ctx
1225 ->lsm->u
1226 .process_attr_tracker_add_remove_include_value
1227 .value_type;
1228 struct process_attr_value *value;
1229 enum lttng_error_code ret_code;
1230
1231 /* Receive remaining variable length payload if applicable. */
1232 if (name_len > LOGIN_NAME_MAX) {
1233 /*
1234 * POSIX mandates user and group names that are at least
1235 * 8 characters long. Note that although shadow-utils
1236 * (useradd, groupaadd, etc.) use 32 chars as their
1237 * limit (from bits/utmp.h, UT_NAMESIZE),
1238 * LOGIN_NAME_MAX is defined to 256.
1239 */
1240 ERR("Rejecting process attribute tracker value %s as the provided exceeds the maximal allowed length: argument length = %zu, maximal length = %d",
1241 add_value ? "addition" : "removal",
1242 name_len, LOGIN_NAME_MAX);
1243 ret = LTTNG_ERR_INVALID;
1244 goto error;
1245 }
1246
1247 lttng_dynamic_buffer_init(&payload);
1248 if (name_len != 0) {
1249 /*
1250 * Receive variable payload for user/group name
1251 * arguments.
1252 */
1253 ret = lttng_dynamic_buffer_set_size(&payload, name_len);
1254 if (ret) {
1255 ERR("Failed to allocate buffer to receive payload of %s process attribute tracker value argument",
1256 add_value ? "add" : "remove");
1257 ret = LTTNG_ERR_NOMEM;
1258 goto error_add_remove_tracker_value;
1259 }
1260
1261 ret = lttcomm_recv_unix_sock(
1262 *sock, payload.data, name_len);
1263 if (ret <= 0) {
1264 ERR("Failed to receive payload of %s process attribute tracker value argument",
1265 add_value ? "add" : "remove");
1266 *sock_error = 1;
1267 ret = LTTNG_ERR_INVALID_PROTOCOL;
1268 goto error_add_remove_tracker_value;
1269 }
1270 }
1271
1272 payload_view = lttng_buffer_view_from_dynamic_buffer(
1273 &payload, 0, name_len);
1274 /*
1275 * Validate the value type and domains are legal for the process
1276 * attribute tracker that is specified and convert the value to
1277 * add/remove to the internal sessiond representation.
1278 */
1279 ret_code = process_attr_value_from_comm(domain_type,
1280 process_attr, value_type,
1281 &cmd_ctx->lsm->u.process_attr_tracker_add_remove_include_value
1282 .integral_value,
1283 &payload_view, &value);
1284 if (ret_code != LTTNG_OK) {
1285 ret = ret_code;
1286 goto error_add_remove_tracker_value;
1287 }
1288
1289 if (add_value) {
1290 ret = cmd_process_attr_tracker_inclusion_set_add_value(
1291 cmd_ctx->session, domain_type,
1292 process_attr, value);
1293 } else {
1294 ret = cmd_process_attr_tracker_inclusion_set_remove_value(
1295 cmd_ctx->session, domain_type,
1296 process_attr, value);
1297 }
1298 process_attr_value_destroy(value);
1299 error_add_remove_tracker_value:
1300 lttng_dynamic_buffer_reset(&payload);
1301 break;
1302 }
1303 case LTTNG_PROCESS_ATTR_TRACKER_GET_POLICY:
1304 {
1305 enum lttng_tracking_policy tracking_policy;
1306 const enum lttng_domain_type domain_type =
1307 (enum lttng_domain_type)
1308 cmd_ctx->lsm->domain.type;
1309 const enum lttng_process_attr process_attr =
1310 (enum lttng_process_attr) cmd_ctx->lsm->u
1311 .process_attr_tracker_get_tracking_policy
1312 .process_attr;
1313
1314 ret = cmd_process_attr_tracker_get_tracking_policy(
1315 cmd_ctx->session, domain_type, process_attr,
1316 &tracking_policy);
1317 if (ret != LTTNG_OK) {
1318 goto error;
1319 }
1320
1321 ret = setup_lttng_msg_no_cmd_header(cmd_ctx,
1322 &(uint32_t){tracking_policy}, sizeof(uint32_t));
1323 if (ret < 0) {
1324 ret = LTTNG_ERR_NOMEM;
1325 goto error;
1326 }
1327 ret = LTTNG_OK;
1328 break;
1329 }
1330 case LTTNG_PROCESS_ATTR_TRACKER_SET_POLICY:
1331 {
1332 const enum lttng_tracking_policy tracking_policy =
1333 (enum lttng_tracking_policy) cmd_ctx->lsm->u
1334 .process_attr_tracker_set_tracking_policy
1335 .tracking_policy;
1336 const enum lttng_domain_type domain_type =
1337 (enum lttng_domain_type)
1338 cmd_ctx->lsm->domain.type;
1339 const enum lttng_process_attr process_attr =
1340 (enum lttng_process_attr) cmd_ctx->lsm->u
1341 .process_attr_tracker_set_tracking_policy
1342 .process_attr;
1343
1344 ret = cmd_process_attr_tracker_set_tracking_policy(
1345 cmd_ctx->session, domain_type, process_attr,
1346 tracking_policy);
1347 if (ret != LTTNG_OK) {
1348 goto error;
1349 }
1350 break;
1351 }
1352 case LTTNG_PROCESS_ATTR_TRACKER_GET_INCLUSION_SET:
1353 {
1354 struct lttng_process_attr_values *values;
1355 struct lttng_dynamic_buffer reply;
1356 const enum lttng_domain_type domain_type =
1357 (enum lttng_domain_type)
1358 cmd_ctx->lsm->domain.type;
1359 const enum lttng_process_attr process_attr =
1360 (enum lttng_process_attr) cmd_ctx->lsm->u
1361 .process_attr_tracker_get_inclusion_set
1362 .process_attr;
1363
1364 ret = cmd_process_attr_tracker_get_inclusion_set(
1365 cmd_ctx->session, domain_type, process_attr,
1366 &values);
1367 if (ret != LTTNG_OK) {
1368 goto error;
1369 }
1370
1371 lttng_dynamic_buffer_init(&reply);
1372 ret = lttng_process_attr_values_serialize(values, &reply);
1373 if (ret < 0) {
1374 goto error_tracker_get_inclusion_set;
1375 }
1376
1377 ret = setup_lttng_msg_no_cmd_header(
1378 cmd_ctx, reply.data, reply.size);
1379 if (ret < 0) {
1380 ret = LTTNG_ERR_NOMEM;
1381 goto error_tracker_get_inclusion_set;
1382 }
1383 ret = LTTNG_OK;
1384
1385 error_tracker_get_inclusion_set:
1386 lttng_process_attr_values_destroy(values);
1387 lttng_dynamic_buffer_reset(&reply);
1388 break;
1389 }
1390 case LTTNG_ENABLE_EVENT:
1391 {
1392 struct lttng_event *ev = NULL;
1393 struct lttng_event_exclusion *exclusion = NULL;
1394 struct lttng_filter_bytecode *bytecode = NULL;
1395 char *filter_expression = NULL;
1396
1397 /* Handle exclusion events and receive it from the client. */
1398 if (cmd_ctx->lsm->u.enable.exclusion_count > 0) {
1399 size_t count = cmd_ctx->lsm->u.enable.exclusion_count;
1400
1401 exclusion = zmalloc(sizeof(struct lttng_event_exclusion) +
1402 (count * LTTNG_SYMBOL_NAME_LEN));
1403 if (!exclusion) {
1404 ret = LTTNG_ERR_EXCLUSION_NOMEM;
1405 goto error;
1406 }
1407
1408 DBG("Receiving var len exclusion event list from client ...");
1409 exclusion->count = count;
1410 ret = lttcomm_recv_unix_sock(*sock, exclusion->names,
1411 count * LTTNG_SYMBOL_NAME_LEN);
1412 if (ret <= 0) {
1413 DBG("Nothing recv() from client var len data... continuing");
1414 *sock_error = 1;
1415 free(exclusion);
1416 ret = LTTNG_ERR_EXCLUSION_INVAL;
1417 goto error;
1418 }
1419 }
1420
1421 /* Get filter expression from client. */
1422 if (cmd_ctx->lsm->u.enable.expression_len > 0) {
1423 size_t expression_len =
1424 cmd_ctx->lsm->u.enable.expression_len;
1425
1426 if (expression_len > LTTNG_FILTER_MAX_LEN) {
1427 ret = LTTNG_ERR_FILTER_INVAL;
1428 free(exclusion);
1429 goto error;
1430 }
1431
1432 filter_expression = zmalloc(expression_len);
1433 if (!filter_expression) {
1434 free(exclusion);
1435 ret = LTTNG_ERR_FILTER_NOMEM;
1436 goto error;
1437 }
1438
1439 /* Receive var. len. data */
1440 DBG("Receiving var len filter's expression from client ...");
1441 ret = lttcomm_recv_unix_sock(*sock, filter_expression,
1442 expression_len);
1443 if (ret <= 0) {
1444 DBG("Nothing recv() from client var len data... continuing");
1445 *sock_error = 1;
1446 free(filter_expression);
1447 free(exclusion);
1448 ret = LTTNG_ERR_FILTER_INVAL;
1449 goto error;
1450 }
1451 }
1452
1453 /* Handle filter and get bytecode from client. */
1454 if (cmd_ctx->lsm->u.enable.bytecode_len > 0) {
1455 size_t bytecode_len = cmd_ctx->lsm->u.enable.bytecode_len;
1456
1457 if (bytecode_len > LTTNG_FILTER_MAX_LEN) {
1458 ret = LTTNG_ERR_FILTER_INVAL;
1459 free(filter_expression);
1460 free(exclusion);
1461 goto error;
1462 }
1463
1464 bytecode = zmalloc(bytecode_len);
1465 if (!bytecode) {
1466 free(filter_expression);
1467 free(exclusion);
1468 ret = LTTNG_ERR_FILTER_NOMEM;
1469 goto error;
1470 }
1471
1472 /* Receive var. len. data */
1473 DBG("Receiving var len filter's bytecode from client ...");
1474 ret = lttcomm_recv_unix_sock(*sock, bytecode, bytecode_len);
1475 if (ret <= 0) {
1476 DBG("Nothing recv() from client var len data... continuing");
1477 *sock_error = 1;
1478 free(filter_expression);
1479 free(bytecode);
1480 free(exclusion);
1481 ret = LTTNG_ERR_FILTER_INVAL;
1482 goto error;
1483 }
1484
1485 if ((bytecode->len + sizeof(*bytecode)) != bytecode_len) {
1486 free(filter_expression);
1487 free(bytecode);
1488 free(exclusion);
1489 ret = LTTNG_ERR_FILTER_INVAL;
1490 goto error;
1491 }
1492 }
1493
1494 ev = lttng_event_copy(ALIGNED_CONST_PTR(cmd_ctx->lsm->u.enable.event));
1495 if (!ev) {
1496 DBG("Failed to copy event: %s",
1497 cmd_ctx->lsm->u.enable.event.name);
1498 free(filter_expression);
1499 free(bytecode);
1500 free(exclusion);
1501 ret = LTTNG_ERR_NOMEM;
1502 goto error;
1503 }
1504
1505
1506 if (cmd_ctx->lsm->u.enable.userspace_probe_location_len > 0) {
1507 /* Expect a userspace probe description. */
1508 ret = receive_userspace_probe(cmd_ctx, *sock, sock_error, ev);
1509 if (ret) {
1510 free(filter_expression);
1511 free(bytecode);
1512 free(exclusion);
1513 lttng_event_destroy(ev);
1514 goto error;
1515 }
1516 }
1517
1518 ret = cmd_enable_event(cmd_ctx->session,
1519 ALIGNED_CONST_PTR(cmd_ctx->lsm->domain),
1520 cmd_ctx->lsm->u.enable.channel_name,
1521 ev,
1522 filter_expression, bytecode, exclusion,
1523 kernel_poll_pipe[1]);
1524 lttng_event_destroy(ev);
1525 break;
1526 }
1527 case LTTNG_LIST_TRACEPOINTS:
1528 {
1529 struct lttng_event *events;
1530 ssize_t nb_events;
1531
1532 session_lock_list();
1533 nb_events = cmd_list_tracepoints(cmd_ctx->lsm->domain.type, &events);
1534 session_unlock_list();
1535 if (nb_events < 0) {
1536 /* Return value is a negative lttng_error_code. */
1537 ret = -nb_events;
1538 goto error;
1539 }
1540
1541 /*
1542 * Setup lttng message with payload size set to the event list size in
1543 * bytes and then copy list into the llm payload.
1544 */
1545 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, events,
1546 sizeof(struct lttng_event) * nb_events);
1547 free(events);
1548
1549 if (ret < 0) {
1550 goto setup_error;
1551 }
1552
1553 ret = LTTNG_OK;
1554 break;
1555 }
1556 case LTTNG_LIST_TRACEPOINT_FIELDS:
1557 {
1558 struct lttng_event_field *fields;
1559 ssize_t nb_fields;
1560
1561 session_lock_list();
1562 nb_fields = cmd_list_tracepoint_fields(cmd_ctx->lsm->domain.type,
1563 &fields);
1564 session_unlock_list();
1565 if (nb_fields < 0) {
1566 /* Return value is a negative lttng_error_code. */
1567 ret = -nb_fields;
1568 goto error;
1569 }
1570
1571 /*
1572 * Setup lttng message with payload size set to the event list size in
1573 * bytes and then copy list into the llm payload.
1574 */
1575 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, fields,
1576 sizeof(struct lttng_event_field) * nb_fields);
1577 free(fields);
1578
1579 if (ret < 0) {
1580 goto setup_error;
1581 }
1582
1583 ret = LTTNG_OK;
1584 break;
1585 }
1586 case LTTNG_LIST_SYSCALLS:
1587 {
1588 struct lttng_event *events;
1589 ssize_t nb_events;
1590
1591 nb_events = cmd_list_syscalls(&events);
1592 if (nb_events < 0) {
1593 /* Return value is a negative lttng_error_code. */
1594 ret = -nb_events;
1595 goto error;
1596 }
1597
1598 /*
1599 * Setup lttng message with payload size set to the event list size in
1600 * bytes and then copy list into the llm payload.
1601 */
1602 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, events,
1603 sizeof(struct lttng_event) * nb_events);
1604 free(events);
1605
1606 if (ret < 0) {
1607 goto setup_error;
1608 }
1609
1610 ret = LTTNG_OK;
1611 break;
1612 }
1613 case LTTNG_SET_CONSUMER_URI:
1614 {
1615 size_t nb_uri, len;
1616 struct lttng_uri *uris;
1617
1618 nb_uri = cmd_ctx->lsm->u.uri.size;
1619 len = nb_uri * sizeof(struct lttng_uri);
1620
1621 if (nb_uri == 0) {
1622 ret = LTTNG_ERR_INVALID;
1623 goto error;
1624 }
1625
1626 uris = zmalloc(len);
1627 if (uris == NULL) {
1628 ret = LTTNG_ERR_FATAL;
1629 goto error;
1630 }
1631
1632 /* Receive variable len data */
1633 DBG("Receiving %zu URI(s) from client ...", nb_uri);
1634 ret = lttcomm_recv_unix_sock(*sock, uris, len);
1635 if (ret <= 0) {
1636 DBG("No URIs received from client... continuing");
1637 *sock_error = 1;
1638 ret = LTTNG_ERR_SESSION_FAIL;
1639 free(uris);
1640 goto error;
1641 }
1642
1643 ret = cmd_set_consumer_uri(cmd_ctx->session, nb_uri, uris);
1644 free(uris);
1645 if (ret != LTTNG_OK) {
1646 goto error;
1647 }
1648
1649
1650 break;
1651 }
1652 case LTTNG_START_TRACE:
1653 {
1654 /*
1655 * On the first start, if we have a kernel session and we have
1656 * enabled time or size-based rotations, we have to make sure
1657 * the kernel tracer supports it.
1658 */
1659 if (!cmd_ctx->session->has_been_started && \
1660 cmd_ctx->session->kernel_session && \
1661 (cmd_ctx->session->rotate_timer_period || \
1662 cmd_ctx->session->rotate_size) && \
1663 !check_rotate_compatible()) {
1664 DBG("Kernel tracer version is not compatible with the rotation feature");
1665 ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
1666 goto error;
1667 }
1668 ret = cmd_start_trace(cmd_ctx->session);
1669 break;
1670 }
1671 case LTTNG_STOP_TRACE:
1672 {
1673 ret = cmd_stop_trace(cmd_ctx->session);
1674 break;
1675 }
1676 case LTTNG_DESTROY_SESSION:
1677 {
1678 ret = cmd_destroy_session(cmd_ctx->session,
1679 notification_thread_handle,
1680 sock);
1681 break;
1682 }
1683 case LTTNG_LIST_DOMAINS:
1684 {
1685 ssize_t nb_dom;
1686 struct lttng_domain *domains = NULL;
1687
1688 nb_dom = cmd_list_domains(cmd_ctx->session, &domains);
1689 if (nb_dom < 0) {
1690 /* Return value is a negative lttng_error_code. */
1691 ret = -nb_dom;
1692 goto error;
1693 }
1694
1695 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, domains,
1696 nb_dom * sizeof(struct lttng_domain));
1697 free(domains);
1698
1699 if (ret < 0) {
1700 goto setup_error;
1701 }
1702
1703 ret = LTTNG_OK;
1704 break;
1705 }
1706 case LTTNG_LIST_CHANNELS:
1707 {
1708 ssize_t payload_size;
1709 struct lttng_channel *channels = NULL;
1710
1711 payload_size = cmd_list_channels(cmd_ctx->lsm->domain.type,
1712 cmd_ctx->session, &channels);
1713 if (payload_size < 0) {
1714 /* Return value is a negative lttng_error_code. */
1715 ret = -payload_size;
1716 goto error;
1717 }
1718
1719 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, channels,
1720 payload_size);
1721 free(channels);
1722
1723 if (ret < 0) {
1724 goto setup_error;
1725 }
1726
1727 ret = LTTNG_OK;
1728 break;
1729 }
1730 case LTTNG_LIST_EVENTS:
1731 {
1732 ssize_t nb_event;
1733 struct lttng_event *events = NULL;
1734 struct lttcomm_event_command_header cmd_header;
1735 size_t total_size;
1736
1737 memset(&cmd_header, 0, sizeof(cmd_header));
1738 /* Extended infos are included at the end of events */
1739 nb_event = cmd_list_events(cmd_ctx->lsm->domain.type,
1740 cmd_ctx->session, cmd_ctx->lsm->u.list.channel_name,
1741 &events, &total_size);
1742
1743 if (nb_event < 0) {
1744 /* Return value is a negative lttng_error_code. */
1745 ret = -nb_event;
1746 goto error;
1747 }
1748
1749 cmd_header.nb_events = nb_event;
1750 ret = setup_lttng_msg(cmd_ctx, events, total_size,
1751 &cmd_header, sizeof(cmd_header));
1752 free(events);
1753
1754 if (ret < 0) {
1755 goto setup_error;
1756 }
1757
1758 ret = LTTNG_OK;
1759 break;
1760 }
1761 case LTTNG_LIST_SESSIONS:
1762 {
1763 unsigned int nr_sessions;
1764 void *sessions_payload;
1765 size_t payload_len;
1766
1767 session_lock_list();
1768 nr_sessions = lttng_sessions_count(
1769 LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
1770 LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds));
1771
1772 payload_len = (sizeof(struct lttng_session) * nr_sessions) +
1773 (sizeof(struct lttng_session_extended) * nr_sessions);
1774 sessions_payload = zmalloc(payload_len);
1775
1776 if (!sessions_payload) {
1777 session_unlock_list();
1778 ret = -ENOMEM;
1779 goto setup_error;
1780 }
1781
1782 cmd_list_lttng_sessions(sessions_payload, nr_sessions,
1783 LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
1784 LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds));
1785 session_unlock_list();
1786
1787 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, sessions_payload,
1788 payload_len);
1789 free(sessions_payload);
1790
1791 if (ret < 0) {
1792 goto setup_error;
1793 }
1794
1795 ret = LTTNG_OK;
1796 break;
1797 }
1798 case LTTNG_REGISTER_CONSUMER:
1799 {
1800 struct consumer_data *cdata;
1801
1802 switch (cmd_ctx->lsm->domain.type) {
1803 case LTTNG_DOMAIN_KERNEL:
1804 cdata = &kconsumer_data;
1805 break;
1806 default:
1807 ret = LTTNG_ERR_UND;
1808 goto error;
1809 }
1810
1811 ret = cmd_register_consumer(cmd_ctx->session, cmd_ctx->lsm->domain.type,
1812 cmd_ctx->lsm->u.reg.path, cdata);
1813 break;
1814 }
1815 case LTTNG_DATA_PENDING:
1816 {
1817 int pending_ret;
1818 uint8_t pending_ret_byte;
1819
1820 pending_ret = cmd_data_pending(cmd_ctx->session);
1821
1822 /*
1823 * FIXME
1824 *
1825 * This function may returns 0 or 1 to indicate whether or not
1826 * there is data pending. In case of error, it should return an
1827 * LTTNG_ERR code. However, some code paths may still return
1828 * a nondescript error code, which we handle by returning an
1829 * "unknown" error.
1830 */
1831 if (pending_ret == 0 || pending_ret == 1) {
1832 /*
1833 * ret will be set to LTTNG_OK at the end of
1834 * this function.
1835 */
1836 } else if (pending_ret < 0) {
1837 ret = LTTNG_ERR_UNK;
1838 goto setup_error;
1839 } else {
1840 ret = pending_ret;
1841 goto setup_error;
1842 }
1843
1844 pending_ret_byte = (uint8_t) pending_ret;
1845
1846 /* 1 byte to return whether or not data is pending */
1847 ret = setup_lttng_msg_no_cmd_header(cmd_ctx,
1848 &pending_ret_byte, 1);
1849
1850 if (ret < 0) {
1851 goto setup_error;
1852 }
1853
1854 ret = LTTNG_OK;
1855 break;
1856 }
1857 case LTTNG_SNAPSHOT_ADD_OUTPUT:
1858 {
1859 uint32_t snapshot_id;
1860 struct lttcomm_lttng_output_id reply;
1861
1862 ret = cmd_snapshot_add_output(cmd_ctx->session,
1863 ALIGNED_CONST_PTR(cmd_ctx->lsm->u.snapshot_output.output),
1864 &snapshot_id);
1865 if (ret != LTTNG_OK) {
1866 goto error;
1867 }
1868 reply.id = snapshot_id;
1869
1870 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &reply,
1871 sizeof(reply));
1872 if (ret < 0) {
1873 goto setup_error;
1874 }
1875
1876 /* Copy output list into message payload */
1877 ret = LTTNG_OK;
1878 break;
1879 }
1880 case LTTNG_SNAPSHOT_DEL_OUTPUT:
1881 {
1882 ret = cmd_snapshot_del_output(cmd_ctx->session,
1883 ALIGNED_CONST_PTR(cmd_ctx->lsm->u.snapshot_output.output));
1884 break;
1885 }
1886 case LTTNG_SNAPSHOT_LIST_OUTPUT:
1887 {
1888 ssize_t nb_output;
1889 struct lttng_snapshot_output *outputs = NULL;
1890
1891 nb_output = cmd_snapshot_list_outputs(cmd_ctx->session, &outputs);
1892 if (nb_output < 0) {
1893 ret = -nb_output;
1894 goto error;
1895 }
1896
1897 assert((nb_output > 0 && outputs) || nb_output == 0);
1898 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, outputs,
1899 nb_output * sizeof(struct lttng_snapshot_output));
1900 free(outputs);
1901
1902 if (ret < 0) {
1903 goto setup_error;
1904 }
1905
1906 ret = LTTNG_OK;
1907 break;
1908 }
1909 case LTTNG_SNAPSHOT_RECORD:
1910 {
1911 ret = cmd_snapshot_record(cmd_ctx->session,
1912 ALIGNED_CONST_PTR(cmd_ctx->lsm->u.snapshot_record.output),
1913 cmd_ctx->lsm->u.snapshot_record.wait);
1914 break;
1915 }
1916 case LTTNG_CREATE_SESSION_EXT:
1917 {
1918 struct lttng_dynamic_buffer payload;
1919 struct lttng_session_descriptor *return_descriptor = NULL;
1920
1921 lttng_dynamic_buffer_init(&payload);
1922 ret = cmd_create_session(cmd_ctx, *sock, &return_descriptor);
1923 if (ret != LTTNG_OK) {
1924 goto error;
1925 }
1926
1927 ret = lttng_session_descriptor_serialize(return_descriptor,
1928 &payload);
1929 if (ret) {
1930 ERR("Failed to serialize session descriptor in reply to \"create session\" command");
1931 lttng_session_descriptor_destroy(return_descriptor);
1932 ret = LTTNG_ERR_NOMEM;
1933 goto error;
1934 }
1935 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, payload.data,
1936 payload.size);
1937 if (ret) {
1938 lttng_session_descriptor_destroy(return_descriptor);
1939 ret = LTTNG_ERR_NOMEM;
1940 goto error;
1941 }
1942 lttng_dynamic_buffer_reset(&payload);
1943 lttng_session_descriptor_destroy(return_descriptor);
1944 ret = LTTNG_OK;
1945 break;
1946 }
1947 case LTTNG_SAVE_SESSION:
1948 {
1949 ret = cmd_save_sessions(&cmd_ctx->lsm->u.save_session.attr,
1950 &cmd_ctx->creds);
1951 break;
1952 }
1953 case LTTNG_SET_SESSION_SHM_PATH:
1954 {
1955 ret = cmd_set_session_shm_path(cmd_ctx->session,
1956 cmd_ctx->lsm->u.set_shm_path.shm_path);
1957 break;
1958 }
1959 case LTTNG_REGENERATE_METADATA:
1960 {
1961 ret = cmd_regenerate_metadata(cmd_ctx->session);
1962 break;
1963 }
1964 case LTTNG_REGENERATE_STATEDUMP:
1965 {
1966 ret = cmd_regenerate_statedump(cmd_ctx->session);
1967 break;
1968 }
1969 case LTTNG_REGISTER_TRIGGER:
1970 {
1971 ret = cmd_register_trigger(cmd_ctx, *sock,
1972 notification_thread_handle);
1973 break;
1974 }
1975 case LTTNG_UNREGISTER_TRIGGER:
1976 {
1977 ret = cmd_unregister_trigger(cmd_ctx, *sock,
1978 notification_thread_handle);
1979 break;
1980 }
1981 case LTTNG_ROTATE_SESSION:
1982 {
1983 struct lttng_rotate_session_return rotate_return;
1984
1985 DBG("Client rotate session \"%s\"", cmd_ctx->session->name);
1986
1987 memset(&rotate_return, 0, sizeof(rotate_return));
1988 if (cmd_ctx->session->kernel_session && !check_rotate_compatible()) {
1989 DBG("Kernel tracer version is not compatible with the rotation feature");
1990 ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
1991 goto error;
1992 }
1993
1994 ret = cmd_rotate_session(cmd_ctx->session, &rotate_return,
1995 false,
1996 LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED);
1997 if (ret < 0) {
1998 ret = -ret;
1999 goto error;
2000 }
2001
2002 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &rotate_return,
2003 sizeof(rotate_return));
2004 if (ret < 0) {
2005 ret = -ret;
2006 goto error;
2007 }
2008
2009 ret = LTTNG_OK;
2010 break;
2011 }
2012 case LTTNG_ROTATION_GET_INFO:
2013 {
2014 struct lttng_rotation_get_info_return get_info_return;
2015
2016 memset(&get_info_return, 0, sizeof(get_info_return));
2017 ret = cmd_rotate_get_info(cmd_ctx->session, &get_info_return,
2018 cmd_ctx->lsm->u.get_rotation_info.rotation_id);
2019 if (ret < 0) {
2020 ret = -ret;
2021 goto error;
2022 }
2023
2024 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &get_info_return,
2025 sizeof(get_info_return));
2026 if (ret < 0) {
2027 ret = -ret;
2028 goto error;
2029 }
2030
2031 ret = LTTNG_OK;
2032 break;
2033 }
2034 case LTTNG_ROTATION_SET_SCHEDULE:
2035 {
2036 bool set_schedule;
2037 enum lttng_rotation_schedule_type schedule_type;
2038 uint64_t value;
2039
2040 if (cmd_ctx->session->kernel_session && !check_rotate_compatible()) {
2041 DBG("Kernel tracer version does not support session rotations");
2042 ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
2043 goto error;
2044 }
2045
2046 set_schedule = cmd_ctx->lsm->u.rotation_set_schedule.set == 1;
2047 schedule_type = (enum lttng_rotation_schedule_type) cmd_ctx->lsm->u.rotation_set_schedule.type;
2048 value = cmd_ctx->lsm->u.rotation_set_schedule.value;
2049
2050 ret = cmd_rotation_set_schedule(cmd_ctx->session,
2051 set_schedule,
2052 schedule_type,
2053 value,
2054 notification_thread_handle);
2055 if (ret != LTTNG_OK) {
2056 goto error;
2057 }
2058
2059 break;
2060 }
2061 case LTTNG_SESSION_LIST_ROTATION_SCHEDULES:
2062 {
2063 struct lttng_session_list_schedules_return schedules = {
2064 .periodic.set = !!cmd_ctx->session->rotate_timer_period,
2065 .periodic.value = cmd_ctx->session->rotate_timer_period,
2066 .size.set = !!cmd_ctx->session->rotate_size,
2067 .size.value = cmd_ctx->session->rotate_size,
2068 };
2069
2070 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &schedules,
2071 sizeof(schedules));
2072 if (ret < 0) {
2073 ret = -ret;
2074 goto error;
2075 }
2076
2077 ret = LTTNG_OK;
2078 break;
2079 }
2080 case LTTNG_CLEAR_SESSION:
2081 {
2082 ret = cmd_clear_session(cmd_ctx->session, sock);
2083 break;
2084 }
2085 default:
2086 ret = LTTNG_ERR_UND;
2087 break;
2088 }
2089
2090 error:
2091 if (cmd_ctx->llm == NULL) {
2092 DBG("Missing llm structure. Allocating one.");
2093 if (setup_lttng_msg_no_cmd_header(cmd_ctx, NULL, 0) < 0) {
2094 goto setup_error;
2095 }
2096 }
2097 /* Set return code */
2098 cmd_ctx->llm->ret_code = ret;
2099 setup_error:
2100 if (cmd_ctx->session) {
2101 session_unlock(cmd_ctx->session);
2102 session_put(cmd_ctx->session);
2103 cmd_ctx->session = NULL;
2104 }
2105 if (need_tracing_session) {
2106 session_unlock_list();
2107 }
2108 init_setup_error:
2109 assert(!rcu_read_ongoing());
2110 return ret;
2111 }
2112
2113 static int create_client_sock(void)
2114 {
2115 int ret, client_sock;
2116 const mode_t old_umask = umask(0);
2117
2118 /* Create client tool unix socket */
2119 client_sock = lttcomm_create_unix_sock(config.client_unix_sock_path.value);
2120 if (client_sock < 0) {
2121 ERR("Create unix sock failed: %s", config.client_unix_sock_path.value);
2122 ret = -1;
2123 goto end;
2124 }
2125
2126 /* Set the cloexec flag */
2127 ret = utils_set_fd_cloexec(client_sock);
2128 if (ret < 0) {
2129 ERR("Unable to set CLOEXEC flag to the client Unix socket (fd: %d). "
2130 "Continuing but note that the consumer daemon will have a "
2131 "reference to this socket on exec()", client_sock);
2132 }
2133
2134 /* File permission MUST be 660 */
2135 ret = chmod(config.client_unix_sock_path.value, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
2136 if (ret < 0) {
2137 ERR("Set file permissions failed: %s",
2138 config.client_unix_sock_path.value);
2139 PERROR("chmod");
2140 (void) lttcomm_close_unix_sock(client_sock);
2141 ret = -1;
2142 goto end;
2143 }
2144 DBG("Created client socket (fd = %i)", client_sock);
2145 ret = client_sock;
2146 end:
2147 umask(old_umask);
2148 return ret;
2149 }
2150
2151 static void cleanup_client_thread(void *data)
2152 {
2153 struct lttng_pipe *quit_pipe = data;
2154
2155 lttng_pipe_destroy(quit_pipe);
2156 }
2157
2158 static void thread_init_cleanup(void *data)
2159 {
2160 set_thread_status(false);
2161 }
2162
2163 /*
2164 * This thread manage all clients request using the unix client socket for
2165 * communication.
2166 */
2167 static void *thread_manage_clients(void *data)
2168 {
2169 int sock = -1, ret, i, pollfd, err = -1;
2170 int sock_error;
2171 uint32_t revents, nb_fd;
2172 struct command_ctx *cmd_ctx = NULL;
2173 struct lttng_poll_event events;
2174 const int client_sock = thread_state.client_sock;
2175 struct lttng_pipe *quit_pipe = data;
2176 const int thread_quit_pipe_fd = lttng_pipe_get_readfd(quit_pipe);
2177
2178 DBG("[thread] Manage client started");
2179
2180 is_root = (getuid() == 0);
2181
2182 pthread_cleanup_push(thread_init_cleanup, NULL);
2183
2184 rcu_register_thread();
2185
2186 health_register(health_sessiond, HEALTH_SESSIOND_TYPE_CMD);
2187
2188 health_code_update();
2189
2190 ret = lttcomm_listen_unix_sock(client_sock);
2191 if (ret < 0) {
2192 goto error_listen;
2193 }
2194
2195 /*
2196 * Pass 2 as size here for the thread quit pipe and client_sock. Nothing
2197 * more will be added to this poll set.
2198 */
2199 ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
2200 if (ret < 0) {
2201 goto error_create_poll;
2202 }
2203
2204 /* Add the application registration socket */
2205 ret = lttng_poll_add(&events, client_sock, LPOLLIN | LPOLLPRI);
2206 if (ret < 0) {
2207 goto error;
2208 }
2209
2210 /* Add thread quit pipe */
2211 ret = lttng_poll_add(&events, thread_quit_pipe_fd, LPOLLIN | LPOLLERR);
2212 if (ret < 0) {
2213 goto error;
2214 }
2215
2216 /* Set state as running. */
2217 set_thread_status(true);
2218 pthread_cleanup_pop(0);
2219
2220 /* This testpoint is after we signal readiness to the parent. */
2221 if (testpoint(sessiond_thread_manage_clients)) {
2222 goto error;
2223 }
2224
2225 if (testpoint(sessiond_thread_manage_clients_before_loop)) {
2226 goto error;
2227 }
2228
2229 health_code_update();
2230
2231 while (1) {
2232 const struct cmd_completion_handler *cmd_completion_handler;
2233
2234 DBG("Accepting client command ...");
2235
2236 /* Inifinite blocking call, waiting for transmission */
2237 restart:
2238 health_poll_entry();
2239 ret = lttng_poll_wait(&events, -1);
2240 health_poll_exit();
2241 if (ret < 0) {
2242 /*
2243 * Restart interrupted system call.
2244 */
2245 if (errno == EINTR) {
2246 goto restart;
2247 }
2248 goto error;
2249 }
2250
2251 nb_fd = ret;
2252
2253 for (i = 0; i < nb_fd; i++) {
2254 revents = LTTNG_POLL_GETEV(&events, i);
2255 pollfd = LTTNG_POLL_GETFD(&events, i);
2256
2257 health_code_update();
2258
2259 if (pollfd == thread_quit_pipe_fd) {
2260 err = 0;
2261 goto exit;
2262 } else {
2263 /* Event on the registration socket */
2264 if (revents & LPOLLIN) {
2265 continue;
2266 } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
2267 ERR("Client socket poll error");
2268 goto error;
2269 } else {
2270 ERR("Unexpected poll events %u for sock %d", revents, pollfd);
2271 goto error;
2272 }
2273 }
2274 }
2275
2276 DBG("Wait for client response");
2277
2278 health_code_update();
2279
2280 sock = lttcomm_accept_unix_sock(client_sock);
2281 if (sock < 0) {
2282 goto error;
2283 }
2284
2285 /*
2286 * Set the CLOEXEC flag. Return code is useless because either way, the
2287 * show must go on.
2288 */
2289 (void) utils_set_fd_cloexec(sock);
2290
2291 /* Set socket option for credentials retrieval */
2292 ret = lttcomm_setsockopt_creds_unix_sock(sock);
2293 if (ret < 0) {
2294 goto error;
2295 }
2296
2297 /* Allocate context command to process the client request */
2298 cmd_ctx = zmalloc(sizeof(struct command_ctx));
2299 if (cmd_ctx == NULL) {
2300 PERROR("zmalloc cmd_ctx");
2301 goto error;
2302 }
2303
2304 /* Allocate data buffer for reception */
2305 cmd_ctx->lsm = zmalloc(sizeof(struct lttcomm_session_msg));
2306 if (cmd_ctx->lsm == NULL) {
2307 PERROR("zmalloc cmd_ctx->lsm");
2308 goto error;
2309 }
2310
2311 cmd_ctx->llm = NULL;
2312 cmd_ctx->session = NULL;
2313
2314 health_code_update();
2315
2316 /*
2317 * Data is received from the lttng client. The struct
2318 * lttcomm_session_msg (lsm) contains the command and data request of
2319 * the client.
2320 */
2321 DBG("Receiving data from client ...");
2322 ret = lttcomm_recv_creds_unix_sock(sock, cmd_ctx->lsm,
2323 sizeof(struct lttcomm_session_msg), &cmd_ctx->creds);
2324 if (ret <= 0) {
2325 DBG("Nothing recv() from client... continuing");
2326 ret = close(sock);
2327 if (ret) {
2328 PERROR("close");
2329 }
2330 sock = -1;
2331 clean_command_ctx(&cmd_ctx);
2332 continue;
2333 }
2334
2335 health_code_update();
2336
2337 // TODO: Validate cmd_ctx including sanity check for
2338 // security purpose.
2339
2340 rcu_thread_online();
2341 /*
2342 * This function dispatch the work to the kernel or userspace tracer
2343 * libs and fill the lttcomm_lttng_msg data structure of all the needed
2344 * informations for the client. The command context struct contains
2345 * everything this function may needs.
2346 */
2347 ret = process_client_msg(cmd_ctx, &sock, &sock_error);
2348 rcu_thread_offline();
2349 if (ret < 0) {
2350 if (sock >= 0) {
2351 ret = close(sock);
2352 if (ret) {
2353 PERROR("close");
2354 }
2355 }
2356 sock = -1;
2357 /*
2358 * TODO: Inform client somehow of the fatal error. At
2359 * this point, ret < 0 means that a zmalloc failed
2360 * (ENOMEM). Error detected but still accept
2361 * command, unless a socket error has been
2362 * detected.
2363 */
2364 clean_command_ctx(&cmd_ctx);
2365 continue;
2366 }
2367
2368 cmd_completion_handler = cmd_pop_completion_handler();
2369 if (cmd_completion_handler) {
2370 enum lttng_error_code completion_code;
2371
2372 completion_code = cmd_completion_handler->run(
2373 cmd_completion_handler->data);
2374 if (completion_code != LTTNG_OK) {
2375 clean_command_ctx(&cmd_ctx);
2376 continue;
2377 }
2378 }
2379
2380 health_code_update();
2381
2382 if (sock >= 0) {
2383 DBG("Sending response (size: %d, retcode: %s (%d))",
2384 cmd_ctx->lttng_msg_size,
2385 lttng_strerror(-cmd_ctx->llm->ret_code),
2386 cmd_ctx->llm->ret_code);
2387 ret = send_unix_sock(sock, cmd_ctx->llm,
2388 cmd_ctx->lttng_msg_size);
2389 if (ret < 0) {
2390 ERR("Failed to send data back to client");
2391 }
2392
2393 /* End of transmission */
2394 ret = close(sock);
2395 if (ret) {
2396 PERROR("close");
2397 }
2398 }
2399 sock = -1;
2400
2401 clean_command_ctx(&cmd_ctx);
2402
2403 health_code_update();
2404 }
2405
2406 exit:
2407 error:
2408 if (sock >= 0) {
2409 ret = close(sock);
2410 if (ret) {
2411 PERROR("close");
2412 }
2413 }
2414
2415 lttng_poll_clean(&events);
2416 clean_command_ctx(&cmd_ctx);
2417
2418 error_listen:
2419 error_create_poll:
2420 unlink(config.client_unix_sock_path.value);
2421 ret = close(client_sock);
2422 if (ret) {
2423 PERROR("close");
2424 }
2425
2426 if (err) {
2427 health_error();
2428 ERR("Health error occurred in %s", __func__);
2429 }
2430
2431 health_unregister(health_sessiond);
2432
2433 DBG("Client thread dying");
2434
2435 rcu_unregister_thread();
2436 return NULL;
2437 }
2438
2439 static
2440 bool shutdown_client_thread(void *thread_data)
2441 {
2442 struct lttng_pipe *client_quit_pipe = thread_data;
2443 const int write_fd = lttng_pipe_get_writefd(client_quit_pipe);
2444
2445 return notify_thread_pipe(write_fd) == 1;
2446 }
2447
2448 struct lttng_thread *launch_client_thread(void)
2449 {
2450 bool thread_running;
2451 struct lttng_pipe *client_quit_pipe;
2452 struct lttng_thread *thread = NULL;
2453 int client_sock_fd = -1;
2454
2455 sem_init(&thread_state.ready, 0, 0);
2456 client_quit_pipe = lttng_pipe_open(FD_CLOEXEC);
2457 if (!client_quit_pipe) {
2458 goto error;
2459 }
2460
2461 client_sock_fd = create_client_sock();
2462 if (client_sock_fd < 0) {
2463 goto error;
2464 }
2465
2466 thread_state.client_sock = client_sock_fd;
2467 thread = lttng_thread_create("Client management",
2468 thread_manage_clients,
2469 shutdown_client_thread,
2470 cleanup_client_thread,
2471 client_quit_pipe);
2472 if (!thread) {
2473 goto error;
2474 }
2475 /* The client thread now owns the client sock fd and the quit pipe. */
2476 client_sock_fd = -1;
2477 client_quit_pipe = NULL;
2478
2479 /*
2480 * This thread is part of the threads that need to be fully
2481 * initialized before the session daemon is marked as "ready".
2482 */
2483 thread_running = wait_thread_status();
2484 if (!thread_running) {
2485 goto error;
2486 }
2487 return thread;
2488 error:
2489 if (client_sock_fd >= 0) {
2490 if (close(client_sock_fd)) {
2491 PERROR("Failed to close client socket");
2492 }
2493 }
2494 lttng_thread_put(thread);
2495 cleanup_client_thread(client_quit_pipe);
2496 return NULL;
2497 }
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