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2c7bd4787c9371305455dfa7765ab9397d07877f
[lttng-tools.git] / src / bin / lttng-sessiond / client.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 * 2013 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License, version 2 only,
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20 #include <stddef.h>
21 #include <pthread.h>
22 #include <signal.h>
23 #include <sys/stat.h>
24 #include <common/compat/getenv.h>
25 #include <common/unix.h>
26 #include <common/utils.h>
27 #include <lttng/userspace-probe-internal.h>
28 #include <lttng/event-internal.h>
29 #include <lttng/session-internal.h>
30 #include <lttng/session-descriptor-internal.h>
31
32 #include "client.h"
33 #include "lttng-sessiond.h"
34 #include "cmd.h"
35 #include "kernel.h"
36 #include "save.h"
37 #include "health-sessiond.h"
38 #include "testpoint.h"
39 #include "utils.h"
40 #include "manage-consumer.h"
41 #include "clear.h"
42
43 static bool is_root;
44
45 static struct thread_state {
46 sem_t ready;
47 bool running;
48 int client_sock;
49 } thread_state;
50
51 static void set_thread_status(bool running)
52 {
53 DBG("Marking client thread's state as %s", running ? "running" : "error");
54 thread_state.running = running;
55 sem_post(&thread_state.ready);
56 }
57
58 static bool wait_thread_status(void)
59 {
60 DBG("Waiting for client thread to be ready");
61 sem_wait(&thread_state.ready);
62 if (thread_state.running) {
63 DBG("Client thread is ready");
64 } else {
65 ERR("Initialization of client thread failed");
66 }
67
68 return thread_state.running;
69 }
70
71 /*
72 * Setup the outgoing data buffer for the response (llm) by allocating the
73 * right amount of memory and copying the original information from the lsm
74 * structure.
75 *
76 * Return 0 on success, negative value on error.
77 */
78 static int setup_lttng_msg(struct command_ctx *cmd_ctx,
79 const void *payload_buf, size_t payload_len,
80 const void *cmd_header_buf, size_t cmd_header_len)
81 {
82 int ret = 0;
83 const size_t header_len = sizeof(struct lttcomm_lttng_msg);
84 const size_t cmd_header_offset = header_len;
85 const size_t payload_offset = cmd_header_offset + cmd_header_len;
86 const size_t total_msg_size = header_len + cmd_header_len + payload_len;
87
88 free(cmd_ctx->llm);
89 cmd_ctx->llm = zmalloc(total_msg_size);
90
91 if (cmd_ctx->llm == NULL) {
92 PERROR("zmalloc");
93 ret = -ENOMEM;
94 goto end;
95 }
96
97 /* Copy common data */
98 cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
99 cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
100 cmd_ctx->llm->cmd_header_size = cmd_header_len;
101 cmd_ctx->llm->data_size = payload_len;
102 cmd_ctx->lttng_msg_size = total_msg_size;
103
104 /* Copy command header */
105 if (cmd_header_len) {
106 memcpy(((uint8_t *) cmd_ctx->llm) + cmd_header_offset, cmd_header_buf,
107 cmd_header_len);
108 }
109
110 /* Copy payload */
111 if (payload_len) {
112 memcpy(((uint8_t *) cmd_ctx->llm) + payload_offset, payload_buf,
113 payload_len);
114 }
115
116 end:
117 return ret;
118 }
119
120 /*
121 * Start the thread_manage_consumer. This must be done after a lttng-consumerd
122 * exec or it will fail.
123 */
124 static int spawn_consumer_thread(struct consumer_data *consumer_data)
125 {
126 return launch_consumer_management_thread(consumer_data) ? 0 : -1;
127 }
128
129 /*
130 * Fork and exec a consumer daemon (consumerd).
131 *
132 * Return pid if successful else -1.
133 */
134 static pid_t spawn_consumerd(struct consumer_data *consumer_data)
135 {
136 int ret;
137 pid_t pid;
138 const char *consumer_to_use;
139 const char *verbosity;
140 struct stat st;
141
142 DBG("Spawning consumerd");
143
144 pid = fork();
145 if (pid == 0) {
146 /*
147 * Exec consumerd.
148 */
149 if (config.verbose_consumer) {
150 verbosity = "--verbose";
151 } else if (lttng_opt_quiet) {
152 verbosity = "--quiet";
153 } else {
154 verbosity = "";
155 }
156
157 switch (consumer_data->type) {
158 case LTTNG_CONSUMER_KERNEL:
159 /*
160 * Find out which consumerd to execute. We will first try the
161 * 64-bit path, then the sessiond's installation directory, and
162 * fallback on the 32-bit one,
163 */
164 DBG3("Looking for a kernel consumer at these locations:");
165 DBG3(" 1) %s", config.consumerd64_bin_path.value ? : "NULL");
166 DBG3(" 2) %s/%s", INSTALL_BIN_PATH, DEFAULT_CONSUMERD_FILE);
167 DBG3(" 3) %s", config.consumerd32_bin_path.value ? : "NULL");
168 if (stat(config.consumerd64_bin_path.value, &st) == 0) {
169 DBG3("Found location #1");
170 consumer_to_use = config.consumerd64_bin_path.value;
171 } else if (stat(INSTALL_BIN_PATH "/" DEFAULT_CONSUMERD_FILE, &st) == 0) {
172 DBG3("Found location #2");
173 consumer_to_use = INSTALL_BIN_PATH "/" DEFAULT_CONSUMERD_FILE;
174 } else if (config.consumerd32_bin_path.value &&
175 stat(config.consumerd32_bin_path.value, &st) == 0) {
176 DBG3("Found location #3");
177 consumer_to_use = config.consumerd32_bin_path.value;
178 } else {
179 DBG("Could not find any valid consumerd executable");
180 ret = -EINVAL;
181 goto error;
182 }
183 DBG("Using kernel consumer at: %s", consumer_to_use);
184 (void) execl(consumer_to_use,
185 "lttng-consumerd", verbosity, "-k",
186 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
187 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
188 "--group", config.tracing_group_name.value,
189 NULL);
190 break;
191 case LTTNG_CONSUMER64_UST:
192 {
193 if (config.consumerd64_lib_dir.value) {
194 char *tmp;
195 size_t tmplen;
196 char *tmpnew;
197
198 tmp = lttng_secure_getenv("LD_LIBRARY_PATH");
199 if (!tmp) {
200 tmp = "";
201 }
202 tmplen = strlen(config.consumerd64_lib_dir.value) + 1 /* : */ + strlen(tmp);
203 tmpnew = zmalloc(tmplen + 1 /* \0 */);
204 if (!tmpnew) {
205 ret = -ENOMEM;
206 goto error;
207 }
208 strcat(tmpnew, config.consumerd64_lib_dir.value);
209 if (tmp[0] != '\0') {
210 strcat(tmpnew, ":");
211 strcat(tmpnew, tmp);
212 }
213 ret = setenv("LD_LIBRARY_PATH", tmpnew, 1);
214 free(tmpnew);
215 if (ret) {
216 ret = -errno;
217 goto error;
218 }
219 }
220 DBG("Using 64-bit UST consumer at: %s", config.consumerd64_bin_path.value);
221 (void) execl(config.consumerd64_bin_path.value, "lttng-consumerd", verbosity, "-u",
222 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
223 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
224 "--group", config.tracing_group_name.value,
225 NULL);
226 break;
227 }
228 case LTTNG_CONSUMER32_UST:
229 {
230 if (config.consumerd32_lib_dir.value) {
231 char *tmp;
232 size_t tmplen;
233 char *tmpnew;
234
235 tmp = lttng_secure_getenv("LD_LIBRARY_PATH");
236 if (!tmp) {
237 tmp = "";
238 }
239 tmplen = strlen(config.consumerd32_lib_dir.value) + 1 /* : */ + strlen(tmp);
240 tmpnew = zmalloc(tmplen + 1 /* \0 */);
241 if (!tmpnew) {
242 ret = -ENOMEM;
243 goto error;
244 }
245 strcat(tmpnew, config.consumerd32_lib_dir.value);
246 if (tmp[0] != '\0') {
247 strcat(tmpnew, ":");
248 strcat(tmpnew, tmp);
249 }
250 ret = setenv("LD_LIBRARY_PATH", tmpnew, 1);
251 free(tmpnew);
252 if (ret) {
253 ret = -errno;
254 goto error;
255 }
256 }
257 DBG("Using 32-bit UST consumer at: %s", config.consumerd32_bin_path.value);
258 (void) execl(config.consumerd32_bin_path.value, "lttng-consumerd", verbosity, "-u",
259 "--consumerd-cmd-sock", consumer_data->cmd_unix_sock_path,
260 "--consumerd-err-sock", consumer_data->err_unix_sock_path,
261 "--group", config.tracing_group_name.value,
262 NULL);
263 break;
264 }
265 default:
266 ERR("unknown consumer type");
267 errno = 0;
268 }
269 if (errno != 0) {
270 PERROR("Consumer execl()");
271 }
272 /* Reaching this point, we got a failure on our execl(). */
273 exit(EXIT_FAILURE);
274 } else if (pid > 0) {
275 ret = pid;
276 } else {
277 PERROR("start consumer fork");
278 ret = -errno;
279 }
280 error:
281 return ret;
282 }
283
284 /*
285 * Spawn the consumerd daemon and session daemon thread.
286 */
287 static int start_consumerd(struct consumer_data *consumer_data)
288 {
289 int ret;
290
291 /*
292 * Set the listen() state on the socket since there is a possible race
293 * between the exec() of the consumer daemon and this call if place in the
294 * consumer thread. See bug #366 for more details.
295 */
296 ret = lttcomm_listen_unix_sock(consumer_data->err_sock);
297 if (ret < 0) {
298 goto error;
299 }
300
301 pthread_mutex_lock(&consumer_data->pid_mutex);
302 if (consumer_data->pid != 0) {
303 pthread_mutex_unlock(&consumer_data->pid_mutex);
304 goto end;
305 }
306
307 ret = spawn_consumerd(consumer_data);
308 if (ret < 0) {
309 ERR("Spawning consumerd failed");
310 pthread_mutex_unlock(&consumer_data->pid_mutex);
311 goto error;
312 }
313
314 /* Setting up the consumer_data pid */
315 consumer_data->pid = ret;
316 DBG2("Consumer pid %d", consumer_data->pid);
317 pthread_mutex_unlock(&consumer_data->pid_mutex);
318
319 DBG2("Spawning consumer control thread");
320 ret = spawn_consumer_thread(consumer_data);
321 if (ret < 0) {
322 ERR("Fatal error spawning consumer control thread");
323 goto error;
324 }
325
326 end:
327 return 0;
328
329 error:
330 /* Cleanup already created sockets on error. */
331 if (consumer_data->err_sock >= 0) {
332 int err;
333
334 err = close(consumer_data->err_sock);
335 if (err < 0) {
336 PERROR("close consumer data error socket");
337 }
338 }
339 return ret;
340 }
341
342 /*
343 * Copy consumer output from the tracing session to the domain session. The
344 * function also applies the right modification on a per domain basis for the
345 * trace files destination directory.
346 *
347 * Should *NOT* be called with RCU read-side lock held.
348 */
349 static int copy_session_consumer(int domain, struct ltt_session *session)
350 {
351 int ret;
352 const char *dir_name;
353 struct consumer_output *consumer;
354
355 assert(session);
356 assert(session->consumer);
357
358 switch (domain) {
359 case LTTNG_DOMAIN_KERNEL:
360 DBG3("Copying tracing session consumer output in kernel session");
361 /*
362 * XXX: We should audit the session creation and what this function
363 * does "extra" in order to avoid a destroy since this function is used
364 * in the domain session creation (kernel and ust) only. Same for UST
365 * domain.
366 */
367 if (session->kernel_session->consumer) {
368 consumer_output_put(session->kernel_session->consumer);
369 }
370 session->kernel_session->consumer =
371 consumer_copy_output(session->consumer);
372 /* Ease our life a bit for the next part */
373 consumer = session->kernel_session->consumer;
374 dir_name = DEFAULT_KERNEL_TRACE_DIR;
375 break;
376 case LTTNG_DOMAIN_JUL:
377 case LTTNG_DOMAIN_LOG4J:
378 case LTTNG_DOMAIN_PYTHON:
379 case LTTNG_DOMAIN_UST:
380 DBG3("Copying tracing session consumer output in UST session");
381 if (session->ust_session->consumer) {
382 consumer_output_put(session->ust_session->consumer);
383 }
384 session->ust_session->consumer =
385 consumer_copy_output(session->consumer);
386 /* Ease our life a bit for the next part */
387 consumer = session->ust_session->consumer;
388 dir_name = DEFAULT_UST_TRACE_DIR;
389 break;
390 default:
391 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
392 goto error;
393 }
394
395 /* Append correct directory to subdir */
396 ret = lttng_strncpy(consumer->domain_subdir, dir_name,
397 sizeof(consumer->domain_subdir));
398 if (ret) {
399 ret = LTTNG_ERR_UNK;
400 goto error;
401 }
402 DBG3("Copy session consumer subdir %s", consumer->domain_subdir);
403 ret = LTTNG_OK;
404
405 error:
406 return ret;
407 }
408
409 /*
410 * Create an UST session and add it to the session ust list.
411 *
412 * Should *NOT* be called with RCU read-side lock held.
413 */
414 static int create_ust_session(struct ltt_session *session,
415 const struct lttng_domain *domain)
416 {
417 int ret;
418 struct ltt_ust_session *lus = NULL;
419
420 assert(session);
421 assert(domain);
422 assert(session->consumer);
423
424 switch (domain->type) {
425 case LTTNG_DOMAIN_JUL:
426 case LTTNG_DOMAIN_LOG4J:
427 case LTTNG_DOMAIN_PYTHON:
428 case LTTNG_DOMAIN_UST:
429 break;
430 default:
431 ERR("Unknown UST domain on create session %d", domain->type);
432 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
433 goto error;
434 }
435
436 DBG("Creating UST session");
437
438 lus = trace_ust_create_session(session->id);
439 if (lus == NULL) {
440 ret = LTTNG_ERR_UST_SESS_FAIL;
441 goto error;
442 }
443
444 lus->uid = session->uid;
445 lus->gid = session->gid;
446 lus->output_traces = session->output_traces;
447 lus->snapshot_mode = session->snapshot_mode;
448 lus->live_timer_interval = session->live_timer;
449 session->ust_session = lus;
450 if (session->shm_path[0]) {
451 strncpy(lus->root_shm_path, session->shm_path,
452 sizeof(lus->root_shm_path));
453 lus->root_shm_path[sizeof(lus->root_shm_path) - 1] = '\0';
454 strncpy(lus->shm_path, session->shm_path,
455 sizeof(lus->shm_path));
456 lus->shm_path[sizeof(lus->shm_path) - 1] = '\0';
457 strncat(lus->shm_path, "/ust",
458 sizeof(lus->shm_path) - strlen(lus->shm_path) - 1);
459 }
460 /* Copy session output to the newly created UST session */
461 ret = copy_session_consumer(domain->type, session);
462 if (ret != LTTNG_OK) {
463 goto error;
464 }
465
466 return LTTNG_OK;
467
468 error:
469 free(lus);
470 session->ust_session = NULL;
471 return ret;
472 }
473
474 /*
475 * Create a kernel tracer session then create the default channel.
476 */
477 static int create_kernel_session(struct ltt_session *session)
478 {
479 int ret;
480
481 DBG("Creating kernel session");
482
483 ret = kernel_create_session(session);
484 if (ret < 0) {
485 ret = LTTNG_ERR_KERN_SESS_FAIL;
486 goto error_create;
487 }
488
489 /* Code flow safety */
490 assert(session->kernel_session);
491
492 /* Copy session output to the newly created Kernel session */
493 ret = copy_session_consumer(LTTNG_DOMAIN_KERNEL, session);
494 if (ret != LTTNG_OK) {
495 goto error;
496 }
497
498 session->kernel_session->uid = session->uid;
499 session->kernel_session->gid = session->gid;
500 session->kernel_session->output_traces = session->output_traces;
501 session->kernel_session->snapshot_mode = session->snapshot_mode;
502
503 return LTTNG_OK;
504
505 error:
506 trace_kernel_destroy_session(session->kernel_session);
507 session->kernel_session = NULL;
508 error_create:
509 return ret;
510 }
511
512 /*
513 * Count number of session permitted by uid/gid.
514 */
515 static unsigned int lttng_sessions_count(uid_t uid, gid_t gid)
516 {
517 unsigned int i = 0;
518 struct ltt_session *session;
519 const struct ltt_session_list *session_list = session_get_list();
520
521 DBG("Counting number of available session for UID %d GID %d",
522 uid, gid);
523 cds_list_for_each_entry(session, &session_list->head, list) {
524 if (!session_get(session)) {
525 continue;
526 }
527 session_lock(session);
528 /* Only count the sessions the user can control. */
529 if (session_access_ok(session, uid, gid) &&
530 !session->destroyed) {
531 i++;
532 }
533 session_unlock(session);
534 session_put(session);
535 }
536 return i;
537 }
538
539 static int receive_userspace_probe(struct command_ctx *cmd_ctx, int sock,
540 int *sock_error, struct lttng_event *event)
541 {
542 int fd, ret;
543 struct lttng_userspace_probe_location *probe_location;
544 const struct lttng_userspace_probe_location_lookup_method *lookup = NULL;
545 struct lttng_dynamic_buffer probe_location_buffer;
546 struct lttng_buffer_view buffer_view;
547
548 /*
549 * Create a buffer to store the serialized version of the probe
550 * location.
551 */
552 lttng_dynamic_buffer_init(&probe_location_buffer);
553 ret = lttng_dynamic_buffer_set_size(&probe_location_buffer,
554 cmd_ctx->lsm->u.enable.userspace_probe_location_len);
555 if (ret) {
556 ret = LTTNG_ERR_NOMEM;
557 goto error;
558 }
559
560 /*
561 * Receive the probe location.
562 */
563 ret = lttcomm_recv_unix_sock(sock, probe_location_buffer.data,
564 probe_location_buffer.size);
565 if (ret <= 0) {
566 DBG("Nothing recv() from client var len data... continuing");
567 *sock_error = 1;
568 lttng_dynamic_buffer_reset(&probe_location_buffer);
569 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
570 goto error;
571 }
572
573 buffer_view = lttng_buffer_view_from_dynamic_buffer(
574 &probe_location_buffer, 0, probe_location_buffer.size);
575
576 /*
577 * Extract the probe location from the serialized version.
578 */
579 ret = lttng_userspace_probe_location_create_from_buffer(
580 &buffer_view, &probe_location);
581 if (ret < 0) {
582 WARN("Failed to create a userspace probe location from the received buffer");
583 lttng_dynamic_buffer_reset( &probe_location_buffer);
584 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
585 goto error;
586 }
587
588 /*
589 * Receive the file descriptor to the target binary from the client.
590 */
591 DBG("Receiving userspace probe target FD from client ...");
592 ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1);
593 if (ret <= 0) {
594 DBG("Nothing recv() from client userspace probe fd... continuing");
595 *sock_error = 1;
596 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
597 goto error;
598 }
599
600 /*
601 * Set the file descriptor received from the client through the unix
602 * socket in the probe location.
603 */
604 lookup = lttng_userspace_probe_location_get_lookup_method(probe_location);
605 if (!lookup) {
606 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
607 goto error;
608 }
609
610 /*
611 * From the kernel tracer's perspective, all userspace probe event types
612 * are all the same: a file and an offset.
613 */
614 switch (lttng_userspace_probe_location_lookup_method_get_type(lookup)) {
615 case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_FUNCTION_ELF:
616 ret = lttng_userspace_probe_location_function_set_binary_fd(
617 probe_location, fd);
618 break;
619 case LTTNG_USERSPACE_PROBE_LOCATION_LOOKUP_METHOD_TYPE_TRACEPOINT_SDT:
620 ret = lttng_userspace_probe_location_tracepoint_set_binary_fd(
621 probe_location, fd);
622 break;
623 default:
624 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
625 goto error;
626 }
627
628 if (ret) {
629 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
630 goto error;
631 }
632
633 /* Attach the probe location to the event. */
634 ret = lttng_event_set_userspace_probe_location(event, probe_location);
635 if (ret) {
636 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
637 goto error;
638 }
639
640 lttng_dynamic_buffer_reset(&probe_location_buffer);
641 error:
642 return ret;
643 }
644
645 /*
646 * Version of setup_lttng_msg() without command header.
647 */
648 static int setup_lttng_msg_no_cmd_header(struct command_ctx *cmd_ctx,
649 void *payload_buf, size_t payload_len)
650 {
651 return setup_lttng_msg(cmd_ctx, payload_buf, payload_len, NULL, 0);
652 }
653
654 /*
655 * Free memory of a command context structure.
656 */
657 static void clean_command_ctx(struct command_ctx **cmd_ctx)
658 {
659 DBG("Clean command context structure");
660 if (*cmd_ctx) {
661 if ((*cmd_ctx)->llm) {
662 free((*cmd_ctx)->llm);
663 }
664 if ((*cmd_ctx)->lsm) {
665 free((*cmd_ctx)->lsm);
666 }
667 free(*cmd_ctx);
668 *cmd_ctx = NULL;
669 }
670 }
671
672 /*
673 * Check if the current kernel tracer supports the session rotation feature.
674 * Return 1 if it does, 0 otherwise.
675 */
676 static int check_rotate_compatible(void)
677 {
678 int ret = 1;
679
680 if (kernel_tracer_version.major != 2 || kernel_tracer_version.minor < 11) {
681 DBG("Kernel tracer version is not compatible with the rotation feature");
682 ret = 0;
683 }
684
685 return ret;
686 }
687
688 /*
689 * Send data on a unix socket using the liblttsessiondcomm API.
690 *
691 * Return lttcomm error code.
692 */
693 static int send_unix_sock(int sock, void *buf, size_t len)
694 {
695 /* Check valid length */
696 if (len == 0) {
697 return -1;
698 }
699
700 return lttcomm_send_unix_sock(sock, buf, len);
701 }
702
703 /*
704 * Process the command requested by the lttng client within the command
705 * context structure. This function make sure that the return structure (llm)
706 * is set and ready for transmission before returning.
707 *
708 * Return any error encountered or 0 for success.
709 *
710 * "sock" is only used for special-case var. len data.
711 * A command may assume the ownership of the socket, in which case its value
712 * should be set to -1.
713 *
714 * Should *NOT* be called with RCU read-side lock held.
715 */
716 static int process_client_msg(struct command_ctx *cmd_ctx, int *sock,
717 int *sock_error)
718 {
719 int ret = LTTNG_OK;
720 int need_tracing_session = 1;
721 int need_domain;
722
723 DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
724
725 assert(!rcu_read_ongoing());
726
727 *sock_error = 0;
728
729 switch (cmd_ctx->lsm->cmd_type) {
730 case LTTNG_CREATE_SESSION_EXT:
731 case LTTNG_DESTROY_SESSION:
732 case LTTNG_LIST_SESSIONS:
733 case LTTNG_LIST_DOMAINS:
734 case LTTNG_START_TRACE:
735 case LTTNG_STOP_TRACE:
736 case LTTNG_DATA_PENDING:
737 case LTTNG_SNAPSHOT_ADD_OUTPUT:
738 case LTTNG_SNAPSHOT_DEL_OUTPUT:
739 case LTTNG_SNAPSHOT_LIST_OUTPUT:
740 case LTTNG_SNAPSHOT_RECORD:
741 case LTTNG_SAVE_SESSION:
742 case LTTNG_SET_SESSION_SHM_PATH:
743 case LTTNG_REGENERATE_METADATA:
744 case LTTNG_REGENERATE_STATEDUMP:
745 case LTTNG_REGISTER_TRIGGER:
746 case LTTNG_UNREGISTER_TRIGGER:
747 case LTTNG_ROTATE_SESSION:
748 case LTTNG_ROTATION_GET_INFO:
749 case LTTNG_ROTATION_SET_SCHEDULE:
750 case LTTNG_SESSION_LIST_ROTATION_SCHEDULES:
751 case LTTNG_CLEAR_SESSION:
752 need_domain = 0;
753 break;
754 default:
755 need_domain = 1;
756 }
757
758 if (config.no_kernel && need_domain
759 && cmd_ctx->lsm->domain.type == LTTNG_DOMAIN_KERNEL) {
760 if (!is_root) {
761 ret = LTTNG_ERR_NEED_ROOT_SESSIOND;
762 } else {
763 ret = LTTNG_ERR_KERN_NA;
764 }
765 goto error;
766 }
767
768 /* Deny register consumer if we already have a spawned consumer. */
769 if (cmd_ctx->lsm->cmd_type == LTTNG_REGISTER_CONSUMER) {
770 pthread_mutex_lock(&kconsumer_data.pid_mutex);
771 if (kconsumer_data.pid > 0) {
772 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
773 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
774 goto error;
775 }
776 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
777 }
778
779 /*
780 * Check for command that don't needs to allocate a returned payload. We do
781 * this here so we don't have to make the call for no payload at each
782 * command.
783 */
784 switch(cmd_ctx->lsm->cmd_type) {
785 case LTTNG_LIST_SESSIONS:
786 case LTTNG_LIST_TRACEPOINTS:
787 case LTTNG_LIST_TRACEPOINT_FIELDS:
788 case LTTNG_LIST_DOMAINS:
789 case LTTNG_LIST_CHANNELS:
790 case LTTNG_LIST_EVENTS:
791 case LTTNG_LIST_SYSCALLS:
792 case LTTNG_LIST_TRACKER_IDS:
793 case LTTNG_DATA_PENDING:
794 case LTTNG_ROTATE_SESSION:
795 case LTTNG_ROTATION_GET_INFO:
796 case LTTNG_SESSION_LIST_ROTATION_SCHEDULES:
797 break;
798 default:
799 /* Setup lttng message with no payload */
800 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, NULL, 0);
801 if (ret < 0) {
802 /* This label does not try to unlock the session */
803 goto init_setup_error;
804 }
805 }
806
807 /* Commands that DO NOT need a session. */
808 switch (cmd_ctx->lsm->cmd_type) {
809 case LTTNG_CREATE_SESSION_EXT:
810 case LTTNG_LIST_SESSIONS:
811 case LTTNG_LIST_TRACEPOINTS:
812 case LTTNG_LIST_SYSCALLS:
813 case LTTNG_LIST_TRACEPOINT_FIELDS:
814 case LTTNG_SAVE_SESSION:
815 case LTTNG_REGISTER_TRIGGER:
816 case LTTNG_UNREGISTER_TRIGGER:
817 need_tracing_session = 0;
818 break;
819 default:
820 DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
821 /*
822 * We keep the session list lock across _all_ commands
823 * for now, because the per-session lock does not
824 * handle teardown properly.
825 */
826 session_lock_list();
827 cmd_ctx->session = session_find_by_name(cmd_ctx->lsm->session.name);
828 if (cmd_ctx->session == NULL) {
829 ret = LTTNG_ERR_SESS_NOT_FOUND;
830 goto error;
831 } else {
832 /* Acquire lock for the session */
833 session_lock(cmd_ctx->session);
834 }
835 break;
836 }
837
838 /*
839 * Commands that need a valid session but should NOT create one if none
840 * exists. Instead of creating one and destroying it when the command is
841 * handled, process that right before so we save some round trip in useless
842 * code path.
843 */
844 switch (cmd_ctx->lsm->cmd_type) {
845 case LTTNG_DISABLE_CHANNEL:
846 case LTTNG_DISABLE_EVENT:
847 switch (cmd_ctx->lsm->domain.type) {
848 case LTTNG_DOMAIN_KERNEL:
849 if (!cmd_ctx->session->kernel_session) {
850 ret = LTTNG_ERR_NO_CHANNEL;
851 goto error;
852 }
853 break;
854 case LTTNG_DOMAIN_JUL:
855 case LTTNG_DOMAIN_LOG4J:
856 case LTTNG_DOMAIN_PYTHON:
857 case LTTNG_DOMAIN_UST:
858 if (!cmd_ctx->session->ust_session) {
859 ret = LTTNG_ERR_NO_CHANNEL;
860 goto error;
861 }
862 break;
863 default:
864 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
865 goto error;
866 }
867 default:
868 break;
869 }
870
871 if (!need_domain) {
872 goto skip_domain;
873 }
874
875 /*
876 * Check domain type for specific "pre-action".
877 */
878 switch (cmd_ctx->lsm->domain.type) {
879 case LTTNG_DOMAIN_KERNEL:
880 if (!is_root) {
881 ret = LTTNG_ERR_NEED_ROOT_SESSIOND;
882 goto error;
883 }
884
885 /* Kernel tracer check */
886 if (!kernel_tracer_is_initialized()) {
887 /* Basically, load kernel tracer modules */
888 ret = init_kernel_tracer();
889 if (ret != 0) {
890 goto error;
891 }
892 }
893
894 /* Consumer is in an ERROR state. Report back to client */
895 if (uatomic_read(&kernel_consumerd_state) == CONSUMER_ERROR) {
896 ret = LTTNG_ERR_NO_KERNCONSUMERD;
897 goto error;
898 }
899
900 /* Need a session for kernel command */
901 if (need_tracing_session) {
902 if (cmd_ctx->session->kernel_session == NULL) {
903 ret = create_kernel_session(cmd_ctx->session);
904 if (ret != LTTNG_OK) {
905 ret = LTTNG_ERR_KERN_SESS_FAIL;
906 goto error;
907 }
908 }
909
910 /* Start the kernel consumer daemon */
911 pthread_mutex_lock(&kconsumer_data.pid_mutex);
912 if (kconsumer_data.pid == 0 &&
913 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
914 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
915 ret = start_consumerd(&kconsumer_data);
916 if (ret < 0) {
917 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
918 goto error;
919 }
920 uatomic_set(&kernel_consumerd_state, CONSUMER_STARTED);
921 } else {
922 pthread_mutex_unlock(&kconsumer_data.pid_mutex);
923 }
924
925 /*
926 * The consumer was just spawned so we need to add the socket to
927 * the consumer output of the session if exist.
928 */
929 ret = consumer_create_socket(&kconsumer_data,
930 cmd_ctx->session->kernel_session->consumer);
931 if (ret < 0) {
932 goto error;
933 }
934 }
935
936 break;
937 case LTTNG_DOMAIN_JUL:
938 case LTTNG_DOMAIN_LOG4J:
939 case LTTNG_DOMAIN_PYTHON:
940 case LTTNG_DOMAIN_UST:
941 {
942 if (!ust_app_supported()) {
943 ret = LTTNG_ERR_NO_UST;
944 goto error;
945 }
946 /* Consumer is in an ERROR state. Report back to client */
947 if (uatomic_read(&ust_consumerd_state) == CONSUMER_ERROR) {
948 ret = LTTNG_ERR_NO_USTCONSUMERD;
949 goto error;
950 }
951
952 if (need_tracing_session) {
953 /* Create UST session if none exist. */
954 if (cmd_ctx->session->ust_session == NULL) {
955 ret = create_ust_session(cmd_ctx->session,
956 ALIGNED_CONST_PTR(cmd_ctx->lsm->domain));
957 if (ret != LTTNG_OK) {
958 goto error;
959 }
960 }
961
962 /* Start the UST consumer daemons */
963 /* 64-bit */
964 pthread_mutex_lock(&ustconsumer64_data.pid_mutex);
965 if (config.consumerd64_bin_path.value &&
966 ustconsumer64_data.pid == 0 &&
967 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
968 pthread_mutex_unlock(&ustconsumer64_data.pid_mutex);
969 ret = start_consumerd(&ustconsumer64_data);
970 if (ret < 0) {
971 ret = LTTNG_ERR_UST_CONSUMER64_FAIL;
972 uatomic_set(&ust_consumerd64_fd, -EINVAL);
973 goto error;
974 }
975
976 uatomic_set(&ust_consumerd64_fd, ustconsumer64_data.cmd_sock);
977 uatomic_set(&ust_consumerd_state, CONSUMER_STARTED);
978 } else {
979 pthread_mutex_unlock(&ustconsumer64_data.pid_mutex);
980 }
981
982 /*
983 * Setup socket for consumer 64 bit. No need for atomic access
984 * since it was set above and can ONLY be set in this thread.
985 */
986 ret = consumer_create_socket(&ustconsumer64_data,
987 cmd_ctx->session->ust_session->consumer);
988 if (ret < 0) {
989 goto error;
990 }
991
992 /* 32-bit */
993 pthread_mutex_lock(&ustconsumer32_data.pid_mutex);
994 if (config.consumerd32_bin_path.value &&
995 ustconsumer32_data.pid == 0 &&
996 cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
997 pthread_mutex_unlock(&ustconsumer32_data.pid_mutex);
998 ret = start_consumerd(&ustconsumer32_data);
999 if (ret < 0) {
1000 ret = LTTNG_ERR_UST_CONSUMER32_FAIL;
1001 uatomic_set(&ust_consumerd32_fd, -EINVAL);
1002 goto error;
1003 }
1004
1005 uatomic_set(&ust_consumerd32_fd, ustconsumer32_data.cmd_sock);
1006 uatomic_set(&ust_consumerd_state, CONSUMER_STARTED);
1007 } else {
1008 pthread_mutex_unlock(&ustconsumer32_data.pid_mutex);
1009 }
1010
1011 /*
1012 * Setup socket for consumer 32 bit. No need for atomic access
1013 * since it was set above and can ONLY be set in this thread.
1014 */
1015 ret = consumer_create_socket(&ustconsumer32_data,
1016 cmd_ctx->session->ust_session->consumer);
1017 if (ret < 0) {
1018 goto error;
1019 }
1020 }
1021 break;
1022 }
1023 default:
1024 break;
1025 }
1026 skip_domain:
1027
1028 /* Validate consumer daemon state when start/stop trace command */
1029 if (cmd_ctx->lsm->cmd_type == LTTNG_START_TRACE ||
1030 cmd_ctx->lsm->cmd_type == LTTNG_STOP_TRACE) {
1031 switch (cmd_ctx->lsm->domain.type) {
1032 case LTTNG_DOMAIN_NONE:
1033 break;
1034 case LTTNG_DOMAIN_JUL:
1035 case LTTNG_DOMAIN_LOG4J:
1036 case LTTNG_DOMAIN_PYTHON:
1037 case LTTNG_DOMAIN_UST:
1038 if (uatomic_read(&ust_consumerd_state) != CONSUMER_STARTED) {
1039 ret = LTTNG_ERR_NO_USTCONSUMERD;
1040 goto error;
1041 }
1042 break;
1043 case LTTNG_DOMAIN_KERNEL:
1044 if (uatomic_read(&kernel_consumerd_state) != CONSUMER_STARTED) {
1045 ret = LTTNG_ERR_NO_KERNCONSUMERD;
1046 goto error;
1047 }
1048 break;
1049 default:
1050 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1051 goto error;
1052 }
1053 }
1054
1055 /*
1056 * Check that the UID or GID match that of the tracing session.
1057 * The root user can interact with all sessions.
1058 */
1059 if (need_tracing_session) {
1060 if (!session_access_ok(cmd_ctx->session,
1061 LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
1062 LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds)) ||
1063 cmd_ctx->session->destroyed) {
1064 ret = LTTNG_ERR_EPERM;
1065 goto error;
1066 }
1067 }
1068
1069 /*
1070 * Send relayd information to consumer as soon as we have a domain and a
1071 * session defined.
1072 */
1073 if (cmd_ctx->session && need_domain) {
1074 /*
1075 * Setup relayd if not done yet. If the relayd information was already
1076 * sent to the consumer, this call will gracefully return.
1077 */
1078 ret = cmd_setup_relayd(cmd_ctx->session);
1079 if (ret != LTTNG_OK) {
1080 goto error;
1081 }
1082 }
1083
1084 /* Process by command type */
1085 switch (cmd_ctx->lsm->cmd_type) {
1086 case LTTNG_ADD_CONTEXT:
1087 {
1088 /*
1089 * An LTTNG_ADD_CONTEXT command might have a supplementary
1090 * payload if the context being added is an application context.
1091 */
1092 if (cmd_ctx->lsm->u.context.ctx.ctx ==
1093 LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
1094 char *provider_name = NULL, *context_name = NULL;
1095 size_t provider_name_len =
1096 cmd_ctx->lsm->u.context.provider_name_len;
1097 size_t context_name_len =
1098 cmd_ctx->lsm->u.context.context_name_len;
1099
1100 if (provider_name_len == 0 || context_name_len == 0) {
1101 /*
1102 * Application provider and context names MUST
1103 * be provided.
1104 */
1105 ret = -LTTNG_ERR_INVALID;
1106 goto error;
1107 }
1108
1109 provider_name = zmalloc(provider_name_len + 1);
1110 if (!provider_name) {
1111 ret = -LTTNG_ERR_NOMEM;
1112 goto error;
1113 }
1114 cmd_ctx->lsm->u.context.ctx.u.app_ctx.provider_name =
1115 provider_name;
1116
1117 context_name = zmalloc(context_name_len + 1);
1118 if (!context_name) {
1119 ret = -LTTNG_ERR_NOMEM;
1120 goto error_add_context;
1121 }
1122 cmd_ctx->lsm->u.context.ctx.u.app_ctx.ctx_name =
1123 context_name;
1124
1125 ret = lttcomm_recv_unix_sock(*sock, provider_name,
1126 provider_name_len);
1127 if (ret < 0) {
1128 goto error_add_context;
1129 }
1130
1131 ret = lttcomm_recv_unix_sock(*sock, context_name,
1132 context_name_len);
1133 if (ret < 0) {
1134 goto error_add_context;
1135 }
1136 }
1137
1138 /*
1139 * cmd_add_context assumes ownership of the provider and context
1140 * names.
1141 */
1142 ret = cmd_add_context(cmd_ctx->session,
1143 cmd_ctx->lsm->domain.type,
1144 cmd_ctx->lsm->u.context.channel_name,
1145 ALIGNED_CONST_PTR(cmd_ctx->lsm->u.context.ctx),
1146 kernel_poll_pipe[1]);
1147
1148 cmd_ctx->lsm->u.context.ctx.u.app_ctx.provider_name = NULL;
1149 cmd_ctx->lsm->u.context.ctx.u.app_ctx.ctx_name = NULL;
1150 error_add_context:
1151 free(cmd_ctx->lsm->u.context.ctx.u.app_ctx.provider_name);
1152 free(cmd_ctx->lsm->u.context.ctx.u.app_ctx.ctx_name);
1153 if (ret < 0) {
1154 goto error;
1155 }
1156 break;
1157 }
1158 case LTTNG_DISABLE_CHANNEL:
1159 {
1160 ret = cmd_disable_channel(cmd_ctx->session, cmd_ctx->lsm->domain.type,
1161 cmd_ctx->lsm->u.disable.channel_name);
1162 break;
1163 }
1164 case LTTNG_DISABLE_EVENT:
1165 {
1166
1167 /*
1168 * FIXME: handle filter; for now we just receive the filter's
1169 * bytecode along with the filter expression which are sent by
1170 * liblttng-ctl and discard them.
1171 *
1172 * This fixes an issue where the client may block while sending
1173 * the filter payload and encounter an error because the session
1174 * daemon closes the socket without ever handling this data.
1175 */
1176 size_t count = cmd_ctx->lsm->u.disable.expression_len +
1177 cmd_ctx->lsm->u.disable.bytecode_len;
1178
1179 if (count) {
1180 char data[LTTNG_FILTER_MAX_LEN];
1181
1182 DBG("Discarding disable event command payload of size %zu", count);
1183 while (count) {
1184 ret = lttcomm_recv_unix_sock(*sock, data,
1185 count > sizeof(data) ? sizeof(data) : count);
1186 if (ret < 0) {
1187 goto error;
1188 }
1189
1190 count -= (size_t) ret;
1191 }
1192 }
1193 ret = cmd_disable_event(cmd_ctx->session, cmd_ctx->lsm->domain.type,
1194 cmd_ctx->lsm->u.disable.channel_name,
1195 ALIGNED_CONST_PTR(cmd_ctx->lsm->u.disable.event));
1196 break;
1197 }
1198 case LTTNG_ENABLE_CHANNEL:
1199 {
1200 cmd_ctx->lsm->u.channel.chan.attr.extended.ptr =
1201 (struct lttng_channel_extended *) &cmd_ctx->lsm->u.channel.extended;
1202 ret = cmd_enable_channel(cmd_ctx->session,
1203 ALIGNED_CONST_PTR(cmd_ctx->lsm->domain),
1204 ALIGNED_CONST_PTR(cmd_ctx->lsm->u.channel.chan),
1205 kernel_poll_pipe[1]);
1206 break;
1207 }
1208 case LTTNG_TRACK_ID:
1209 {
1210 struct lttng_tracker_id *id = NULL;
1211 enum lttng_tracker_id_status status;
1212
1213 id = lttng_tracker_id_create();
1214 if (!id) {
1215 ret = LTTNG_ERR_NOMEM;
1216 goto error;
1217 }
1218
1219 switch (cmd_ctx->lsm->u.id_tracker.id_type) {
1220 case LTTNG_ID_ALL:
1221 status = lttng_tracker_id_set_all(id);
1222 break;
1223 case LTTNG_ID_VALUE:
1224 status = lttng_tracker_id_set_value(
1225 id, cmd_ctx->lsm->u.id_tracker.u.value);
1226 break;
1227 case LTTNG_ID_STRING:
1228 {
1229 const size_t var_len = cmd_ctx->lsm->u.id_tracker.u.var_len;
1230 char *string = NULL;
1231
1232 string = zmalloc(var_len);
1233 if (!string) {
1234 lttng_tracker_id_destroy(id);
1235 ret = LTTNG_ERR_NOMEM;
1236 goto error;
1237 }
1238 DBG("Receiving var len tracker id string from client");
1239 ret = lttcomm_recv_unix_sock(*sock, string, var_len);
1240 if (ret <= 0) {
1241 DBG("Nothing received");
1242 *sock_error = 1;
1243 free(string);
1244 lttng_tracker_id_destroy(id);
1245 ret = LTTNG_ERR_INVALID;
1246 goto error;
1247 }
1248 if (strnlen(string, var_len) != var_len - 1) {
1249 DBG("String received as tracker ID is not NULL-terminated");
1250 free(string);
1251 lttng_tracker_id_destroy(id);
1252 ret = LTTNG_ERR_INVALID;
1253 goto error;
1254 }
1255
1256 status = lttng_tracker_id_set_string(id, string);
1257 free(string);
1258 break;
1259 }
1260 default:
1261 lttng_tracker_id_destroy(id);
1262 ret = LTTNG_ERR_INVALID;
1263 goto error;
1264 }
1265
1266 if (status != LTTNG_TRACKER_ID_STATUS_OK) {
1267 ERR("Invalid value for tracker id");
1268 ret = LTTNG_ERR_INVALID;
1269 lttng_tracker_id_destroy(id);
1270 goto error;
1271 }
1272
1273 ret = cmd_track_id(cmd_ctx->session,
1274 cmd_ctx->lsm->u.id_tracker.tracker_type,
1275 cmd_ctx->lsm->domain.type, id);
1276 lttng_tracker_id_destroy(id);
1277 break;
1278 }
1279 case LTTNG_UNTRACK_ID:
1280 {
1281 struct lttng_tracker_id *id = NULL;
1282 enum lttng_tracker_id_status status;
1283
1284 id = lttng_tracker_id_create();
1285
1286 switch (cmd_ctx->lsm->u.id_tracker.id_type) {
1287 case LTTNG_ID_ALL:
1288 status = lttng_tracker_id_set_all(id);
1289 break;
1290 case LTTNG_ID_VALUE:
1291 status = lttng_tracker_id_set_value(
1292 id, cmd_ctx->lsm->u.id_tracker.u.value);
1293 break;
1294 case LTTNG_ID_STRING:
1295 {
1296 const size_t var_len = cmd_ctx->lsm->u.id_tracker.u.var_len;
1297 char *string = NULL;
1298
1299 string = zmalloc(var_len);
1300 if (!string) {
1301 ret = LTTNG_ERR_NOMEM;
1302 lttng_tracker_id_destroy(id);
1303 goto error;
1304 }
1305 DBG("Receiving var len tracker id string from client");
1306 ret = lttcomm_recv_unix_sock(*sock, string, var_len);
1307 if (ret <= 0) {
1308 DBG("Nothing received");
1309 *sock_error = 1;
1310 lttng_tracker_id_destroy(id);
1311 free(string);
1312 ret = LTTNG_ERR_INVALID;
1313 goto error;
1314 }
1315 if (strnlen(string, var_len) != var_len - 1) {
1316 DBG("String received as tracker ID is not NULL-terminated");
1317 lttng_tracker_id_destroy(id);
1318 free(string);
1319 ret = LTTNG_ERR_INVALID;
1320 goto error;
1321 }
1322 status = lttng_tracker_id_set_string(id, string);
1323 free(string);
1324 break;
1325 }
1326 default:
1327 lttng_tracker_id_destroy(id);
1328 ret = LTTNG_ERR_INVALID;
1329 goto error;
1330 }
1331
1332 if (status != LTTNG_TRACKER_ID_STATUS_OK) {
1333 ERR("Invalid tracker id");
1334 lttng_tracker_id_destroy(id);
1335 ret = LTTNG_ERR_INVALID;
1336 goto error;
1337 }
1338
1339 ret = cmd_untrack_id(cmd_ctx->session,
1340 cmd_ctx->lsm->u.id_tracker.tracker_type,
1341 cmd_ctx->lsm->domain.type, id);
1342 lttng_tracker_id_destroy(id);
1343 break;
1344 }
1345 case LTTNG_ENABLE_EVENT:
1346 {
1347 struct lttng_event *ev = NULL;
1348 struct lttng_event_exclusion *exclusion = NULL;
1349 struct lttng_filter_bytecode *bytecode = NULL;
1350 char *filter_expression = NULL;
1351
1352 /* Handle exclusion events and receive it from the client. */
1353 if (cmd_ctx->lsm->u.enable.exclusion_count > 0) {
1354 size_t count = cmd_ctx->lsm->u.enable.exclusion_count;
1355
1356 exclusion = zmalloc(sizeof(struct lttng_event_exclusion) +
1357 (count * LTTNG_SYMBOL_NAME_LEN));
1358 if (!exclusion) {
1359 ret = LTTNG_ERR_EXCLUSION_NOMEM;
1360 goto error;
1361 }
1362
1363 DBG("Receiving var len exclusion event list from client ...");
1364 exclusion->count = count;
1365 ret = lttcomm_recv_unix_sock(*sock, exclusion->names,
1366 count * LTTNG_SYMBOL_NAME_LEN);
1367 if (ret <= 0) {
1368 DBG("Nothing recv() from client var len data... continuing");
1369 *sock_error = 1;
1370 free(exclusion);
1371 ret = LTTNG_ERR_EXCLUSION_INVAL;
1372 goto error;
1373 }
1374 }
1375
1376 /* Get filter expression from client. */
1377 if (cmd_ctx->lsm->u.enable.expression_len > 0) {
1378 size_t expression_len =
1379 cmd_ctx->lsm->u.enable.expression_len;
1380
1381 if (expression_len > LTTNG_FILTER_MAX_LEN) {
1382 ret = LTTNG_ERR_FILTER_INVAL;
1383 free(exclusion);
1384 goto error;
1385 }
1386
1387 filter_expression = zmalloc(expression_len);
1388 if (!filter_expression) {
1389 free(exclusion);
1390 ret = LTTNG_ERR_FILTER_NOMEM;
1391 goto error;
1392 }
1393
1394 /* Receive var. len. data */
1395 DBG("Receiving var len filter's expression from client ...");
1396 ret = lttcomm_recv_unix_sock(*sock, filter_expression,
1397 expression_len);
1398 if (ret <= 0) {
1399 DBG("Nothing recv() from client var len data... continuing");
1400 *sock_error = 1;
1401 free(filter_expression);
1402 free(exclusion);
1403 ret = LTTNG_ERR_FILTER_INVAL;
1404 goto error;
1405 }
1406 }
1407
1408 /* Handle filter and get bytecode from client. */
1409 if (cmd_ctx->lsm->u.enable.bytecode_len > 0) {
1410 size_t bytecode_len = cmd_ctx->lsm->u.enable.bytecode_len;
1411
1412 if (bytecode_len > LTTNG_FILTER_MAX_LEN) {
1413 ret = LTTNG_ERR_FILTER_INVAL;
1414 free(filter_expression);
1415 free(exclusion);
1416 goto error;
1417 }
1418
1419 bytecode = zmalloc(bytecode_len);
1420 if (!bytecode) {
1421 free(filter_expression);
1422 free(exclusion);
1423 ret = LTTNG_ERR_FILTER_NOMEM;
1424 goto error;
1425 }
1426
1427 /* Receive var. len. data */
1428 DBG("Receiving var len filter's bytecode from client ...");
1429 ret = lttcomm_recv_unix_sock(*sock, bytecode, bytecode_len);
1430 if (ret <= 0) {
1431 DBG("Nothing recv() from client var len data... continuing");
1432 *sock_error = 1;
1433 free(filter_expression);
1434 free(bytecode);
1435 free(exclusion);
1436 ret = LTTNG_ERR_FILTER_INVAL;
1437 goto error;
1438 }
1439
1440 if ((bytecode->len + sizeof(*bytecode)) != bytecode_len) {
1441 free(filter_expression);
1442 free(bytecode);
1443 free(exclusion);
1444 ret = LTTNG_ERR_FILTER_INVAL;
1445 goto error;
1446 }
1447 }
1448
1449 ev = lttng_event_copy(ALIGNED_CONST_PTR(cmd_ctx->lsm->u.enable.event));
1450 if (!ev) {
1451 DBG("Failed to copy event: %s",
1452 cmd_ctx->lsm->u.enable.event.name);
1453 free(filter_expression);
1454 free(bytecode);
1455 free(exclusion);
1456 ret = LTTNG_ERR_NOMEM;
1457 goto error;
1458 }
1459
1460
1461 if (cmd_ctx->lsm->u.enable.userspace_probe_location_len > 0) {
1462 /* Expect a userspace probe description. */
1463 ret = receive_userspace_probe(cmd_ctx, *sock, sock_error, ev);
1464 if (ret) {
1465 free(filter_expression);
1466 free(bytecode);
1467 free(exclusion);
1468 lttng_event_destroy(ev);
1469 goto error;
1470 }
1471 }
1472
1473 ret = cmd_enable_event(cmd_ctx->session,
1474 ALIGNED_CONST_PTR(cmd_ctx->lsm->domain),
1475 cmd_ctx->lsm->u.enable.channel_name,
1476 ev,
1477 filter_expression, bytecode, exclusion,
1478 kernel_poll_pipe[1]);
1479 lttng_event_destroy(ev);
1480 break;
1481 }
1482 case LTTNG_LIST_TRACEPOINTS:
1483 {
1484 struct lttng_event *events;
1485 ssize_t nb_events;
1486
1487 session_lock_list();
1488 nb_events = cmd_list_tracepoints(cmd_ctx->lsm->domain.type, &events);
1489 session_unlock_list();
1490 if (nb_events < 0) {
1491 /* Return value is a negative lttng_error_code. */
1492 ret = -nb_events;
1493 goto error;
1494 }
1495
1496 /*
1497 * Setup lttng message with payload size set to the event list size in
1498 * bytes and then copy list into the llm payload.
1499 */
1500 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, events,
1501 sizeof(struct lttng_event) * nb_events);
1502 free(events);
1503
1504 if (ret < 0) {
1505 goto setup_error;
1506 }
1507
1508 ret = LTTNG_OK;
1509 break;
1510 }
1511 case LTTNG_LIST_TRACEPOINT_FIELDS:
1512 {
1513 struct lttng_event_field *fields;
1514 ssize_t nb_fields;
1515
1516 session_lock_list();
1517 nb_fields = cmd_list_tracepoint_fields(cmd_ctx->lsm->domain.type,
1518 &fields);
1519 session_unlock_list();
1520 if (nb_fields < 0) {
1521 /* Return value is a negative lttng_error_code. */
1522 ret = -nb_fields;
1523 goto error;
1524 }
1525
1526 /*
1527 * Setup lttng message with payload size set to the event list size in
1528 * bytes and then copy list into the llm payload.
1529 */
1530 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, fields,
1531 sizeof(struct lttng_event_field) * nb_fields);
1532 free(fields);
1533
1534 if (ret < 0) {
1535 goto setup_error;
1536 }
1537
1538 ret = LTTNG_OK;
1539 break;
1540 }
1541 case LTTNG_LIST_SYSCALLS:
1542 {
1543 struct lttng_event *events;
1544 ssize_t nb_events;
1545
1546 nb_events = cmd_list_syscalls(&events);
1547 if (nb_events < 0) {
1548 /* Return value is a negative lttng_error_code. */
1549 ret = -nb_events;
1550 goto error;
1551 }
1552
1553 /*
1554 * Setup lttng message with payload size set to the event list size in
1555 * bytes and then copy list into the llm payload.
1556 */
1557 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, events,
1558 sizeof(struct lttng_event) * nb_events);
1559 free(events);
1560
1561 if (ret < 0) {
1562 goto setup_error;
1563 }
1564
1565 ret = LTTNG_OK;
1566 break;
1567 }
1568 case LTTNG_LIST_TRACKER_IDS:
1569 {
1570 struct lttcomm_tracker_command_header cmd_header;
1571 struct lttng_tracker_id **ids = NULL;
1572 ssize_t nr_ids, i;
1573 struct lttng_dynamic_buffer buf;
1574
1575 nr_ids = cmd_list_tracker_ids(
1576 cmd_ctx->lsm->u.id_tracker.tracker_type,
1577 cmd_ctx->session, cmd_ctx->lsm->domain.type,
1578 &ids);
1579 if (nr_ids < 0) {
1580 /* Return value is a negative lttng_error_code. */
1581 ret = -nr_ids;
1582 goto error;
1583 }
1584
1585 lttng_dynamic_buffer_init(&buf);
1586 for (i = 0; i < nr_ids; i++) {
1587 struct lttng_tracker_id *id = ids[i];
1588 struct lttcomm_tracker_id_header id_hdr;
1589 size_t var_data_len = 0;
1590 enum lttng_tracker_id_status status;
1591 const char *string;
1592 int value;
1593
1594 memset(&id_hdr, 0, sizeof(id_hdr));
1595 id_hdr.type = lttng_tracker_id_get_type(id);
1596 switch (id_hdr.type) {
1597 case LTTNG_ID_ALL:
1598 break;
1599 case LTTNG_ID_VALUE:
1600 status = lttng_tracker_id_get_value(id, &value);
1601 id_hdr.u.value = value;
1602 if (status != LTTNG_TRACKER_ID_STATUS_OK) {
1603 ret = LTTNG_ERR_INVALID;
1604 goto error_list_tracker;
1605 }
1606 break;
1607 case LTTNG_ID_STRING:
1608 status = lttng_tracker_id_get_string(
1609 id, &string);
1610 if (status != LTTNG_TRACKER_ID_STATUS_OK) {
1611 ret = LTTNG_ERR_INVALID;
1612 goto error_list_tracker;
1613 }
1614
1615 id_hdr.u.var_data_len = var_data_len =
1616 strlen(string) + 1;
1617 break;
1618 default:
1619 ret = LTTNG_ERR_INVALID;
1620 goto error_list_tracker;
1621 }
1622 ret = lttng_dynamic_buffer_append(
1623 &buf, &id_hdr, sizeof(id_hdr));
1624 if (ret) {
1625 ret = LTTNG_ERR_NOMEM;
1626 goto error_list_tracker;
1627 }
1628 ret = lttng_dynamic_buffer_append(
1629 &buf, string, var_data_len);
1630 if (ret) {
1631 ret = LTTNG_ERR_NOMEM;
1632 goto error_list_tracker;
1633 }
1634 }
1635
1636 cmd_header.nb_tracker_id = nr_ids;
1637 ret = setup_lttng_msg(cmd_ctx, buf.data, buf.size, &cmd_header,
1638 sizeof(cmd_header));
1639 error_list_tracker:
1640 lttng_tracker_ids_destroy(ids, nr_ids);
1641 free(ids);
1642 lttng_dynamic_buffer_reset(&buf);
1643 if (ret < 0) {
1644 goto setup_error;
1645 }
1646
1647 ret = LTTNG_OK;
1648 break;
1649 }
1650 case LTTNG_SET_CONSUMER_URI:
1651 {
1652 size_t nb_uri, len;
1653 struct lttng_uri *uris;
1654
1655 nb_uri = cmd_ctx->lsm->u.uri.size;
1656 len = nb_uri * sizeof(struct lttng_uri);
1657
1658 if (nb_uri == 0) {
1659 ret = LTTNG_ERR_INVALID;
1660 goto error;
1661 }
1662
1663 uris = zmalloc(len);
1664 if (uris == NULL) {
1665 ret = LTTNG_ERR_FATAL;
1666 goto error;
1667 }
1668
1669 /* Receive variable len data */
1670 DBG("Receiving %zu URI(s) from client ...", nb_uri);
1671 ret = lttcomm_recv_unix_sock(*sock, uris, len);
1672 if (ret <= 0) {
1673 DBG("No URIs received from client... continuing");
1674 *sock_error = 1;
1675 ret = LTTNG_ERR_SESSION_FAIL;
1676 free(uris);
1677 goto error;
1678 }
1679
1680 ret = cmd_set_consumer_uri(cmd_ctx->session, nb_uri, uris);
1681 free(uris);
1682 if (ret != LTTNG_OK) {
1683 goto error;
1684 }
1685
1686
1687 break;
1688 }
1689 case LTTNG_START_TRACE:
1690 {
1691 /*
1692 * On the first start, if we have a kernel session and we have
1693 * enabled time or size-based rotations, we have to make sure
1694 * the kernel tracer supports it.
1695 */
1696 if (!cmd_ctx->session->has_been_started && \
1697 cmd_ctx->session->kernel_session && \
1698 (cmd_ctx->session->rotate_timer_period || \
1699 cmd_ctx->session->rotate_size) && \
1700 !check_rotate_compatible()) {
1701 DBG("Kernel tracer version is not compatible with the rotation feature");
1702 ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
1703 goto error;
1704 }
1705 ret = cmd_start_trace(cmd_ctx->session);
1706 break;
1707 }
1708 case LTTNG_STOP_TRACE:
1709 {
1710 ret = cmd_stop_trace(cmd_ctx->session);
1711 break;
1712 }
1713 case LTTNG_DESTROY_SESSION:
1714 {
1715 ret = cmd_destroy_session(cmd_ctx->session,
1716 notification_thread_handle,
1717 sock);
1718 break;
1719 }
1720 case LTTNG_LIST_DOMAINS:
1721 {
1722 ssize_t nb_dom;
1723 struct lttng_domain *domains = NULL;
1724
1725 nb_dom = cmd_list_domains(cmd_ctx->session, &domains);
1726 if (nb_dom < 0) {
1727 /* Return value is a negative lttng_error_code. */
1728 ret = -nb_dom;
1729 goto error;
1730 }
1731
1732 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, domains,
1733 nb_dom * sizeof(struct lttng_domain));
1734 free(domains);
1735
1736 if (ret < 0) {
1737 goto setup_error;
1738 }
1739
1740 ret = LTTNG_OK;
1741 break;
1742 }
1743 case LTTNG_LIST_CHANNELS:
1744 {
1745 ssize_t payload_size;
1746 struct lttng_channel *channels = NULL;
1747
1748 payload_size = cmd_list_channels(cmd_ctx->lsm->domain.type,
1749 cmd_ctx->session, &channels);
1750 if (payload_size < 0) {
1751 /* Return value is a negative lttng_error_code. */
1752 ret = -payload_size;
1753 goto error;
1754 }
1755
1756 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, channels,
1757 payload_size);
1758 free(channels);
1759
1760 if (ret < 0) {
1761 goto setup_error;
1762 }
1763
1764 ret = LTTNG_OK;
1765 break;
1766 }
1767 case LTTNG_LIST_EVENTS:
1768 {
1769 ssize_t nb_event;
1770 struct lttng_event *events = NULL;
1771 struct lttcomm_event_command_header cmd_header;
1772 size_t total_size;
1773
1774 memset(&cmd_header, 0, sizeof(cmd_header));
1775 /* Extended infos are included at the end of events */
1776 nb_event = cmd_list_events(cmd_ctx->lsm->domain.type,
1777 cmd_ctx->session, cmd_ctx->lsm->u.list.channel_name,
1778 &events, &total_size);
1779
1780 if (nb_event < 0) {
1781 /* Return value is a negative lttng_error_code. */
1782 ret = -nb_event;
1783 goto error;
1784 }
1785
1786 cmd_header.nb_events = nb_event;
1787 ret = setup_lttng_msg(cmd_ctx, events, total_size,
1788 &cmd_header, sizeof(cmd_header));
1789 free(events);
1790
1791 if (ret < 0) {
1792 goto setup_error;
1793 }
1794
1795 ret = LTTNG_OK;
1796 break;
1797 }
1798 case LTTNG_LIST_SESSIONS:
1799 {
1800 unsigned int nr_sessions;
1801 void *sessions_payload;
1802 size_t payload_len;
1803
1804 session_lock_list();
1805 nr_sessions = lttng_sessions_count(
1806 LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
1807 LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds));
1808
1809 payload_len = (sizeof(struct lttng_session) * nr_sessions) +
1810 (sizeof(struct lttng_session_extended) * nr_sessions);
1811 sessions_payload = zmalloc(payload_len);
1812
1813 if (!sessions_payload) {
1814 session_unlock_list();
1815 ret = -ENOMEM;
1816 goto setup_error;
1817 }
1818
1819 cmd_list_lttng_sessions(sessions_payload, nr_sessions,
1820 LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
1821 LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds));
1822 session_unlock_list();
1823
1824 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, sessions_payload,
1825 payload_len);
1826 free(sessions_payload);
1827
1828 if (ret < 0) {
1829 goto setup_error;
1830 }
1831
1832 ret = LTTNG_OK;
1833 break;
1834 }
1835 case LTTNG_REGISTER_CONSUMER:
1836 {
1837 struct consumer_data *cdata;
1838
1839 switch (cmd_ctx->lsm->domain.type) {
1840 case LTTNG_DOMAIN_KERNEL:
1841 cdata = &kconsumer_data;
1842 break;
1843 default:
1844 ret = LTTNG_ERR_UND;
1845 goto error;
1846 }
1847
1848 ret = cmd_register_consumer(cmd_ctx->session, cmd_ctx->lsm->domain.type,
1849 cmd_ctx->lsm->u.reg.path, cdata);
1850 break;
1851 }
1852 case LTTNG_DATA_PENDING:
1853 {
1854 int pending_ret;
1855 uint8_t pending_ret_byte;
1856
1857 pending_ret = cmd_data_pending(cmd_ctx->session);
1858
1859 /*
1860 * FIXME
1861 *
1862 * This function may returns 0 or 1 to indicate whether or not
1863 * there is data pending. In case of error, it should return an
1864 * LTTNG_ERR code. However, some code paths may still return
1865 * a nondescript error code, which we handle by returning an
1866 * "unknown" error.
1867 */
1868 if (pending_ret == 0 || pending_ret == 1) {
1869 /*
1870 * ret will be set to LTTNG_OK at the end of
1871 * this function.
1872 */
1873 } else if (pending_ret < 0) {
1874 ret = LTTNG_ERR_UNK;
1875 goto setup_error;
1876 } else {
1877 ret = pending_ret;
1878 goto setup_error;
1879 }
1880
1881 pending_ret_byte = (uint8_t) pending_ret;
1882
1883 /* 1 byte to return whether or not data is pending */
1884 ret = setup_lttng_msg_no_cmd_header(cmd_ctx,
1885 &pending_ret_byte, 1);
1886
1887 if (ret < 0) {
1888 goto setup_error;
1889 }
1890
1891 ret = LTTNG_OK;
1892 break;
1893 }
1894 case LTTNG_SNAPSHOT_ADD_OUTPUT:
1895 {
1896 uint32_t snapshot_id;
1897 struct lttcomm_lttng_output_id reply;
1898
1899 ret = cmd_snapshot_add_output(cmd_ctx->session,
1900 ALIGNED_CONST_PTR(cmd_ctx->lsm->u.snapshot_output.output),
1901 &snapshot_id);
1902 if (ret != LTTNG_OK) {
1903 goto error;
1904 }
1905 reply.id = snapshot_id;
1906
1907 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &reply,
1908 sizeof(reply));
1909 if (ret < 0) {
1910 goto setup_error;
1911 }
1912
1913 /* Copy output list into message payload */
1914 ret = LTTNG_OK;
1915 break;
1916 }
1917 case LTTNG_SNAPSHOT_DEL_OUTPUT:
1918 {
1919 ret = cmd_snapshot_del_output(cmd_ctx->session,
1920 ALIGNED_CONST_PTR(cmd_ctx->lsm->u.snapshot_output.output));
1921 break;
1922 }
1923 case LTTNG_SNAPSHOT_LIST_OUTPUT:
1924 {
1925 ssize_t nb_output;
1926 struct lttng_snapshot_output *outputs = NULL;
1927
1928 nb_output = cmd_snapshot_list_outputs(cmd_ctx->session, &outputs);
1929 if (nb_output < 0) {
1930 ret = -nb_output;
1931 goto error;
1932 }
1933
1934 assert((nb_output > 0 && outputs) || nb_output == 0);
1935 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, outputs,
1936 nb_output * sizeof(struct lttng_snapshot_output));
1937 free(outputs);
1938
1939 if (ret < 0) {
1940 goto setup_error;
1941 }
1942
1943 ret = LTTNG_OK;
1944 break;
1945 }
1946 case LTTNG_SNAPSHOT_RECORD:
1947 {
1948 ret = cmd_snapshot_record(cmd_ctx->session,
1949 ALIGNED_CONST_PTR(cmd_ctx->lsm->u.snapshot_record.output),
1950 cmd_ctx->lsm->u.snapshot_record.wait);
1951 break;
1952 }
1953 case LTTNG_CREATE_SESSION_EXT:
1954 {
1955 struct lttng_dynamic_buffer payload;
1956 struct lttng_session_descriptor *return_descriptor = NULL;
1957
1958 lttng_dynamic_buffer_init(&payload);
1959 ret = cmd_create_session(cmd_ctx, *sock, &return_descriptor);
1960 if (ret != LTTNG_OK) {
1961 goto error;
1962 }
1963
1964 ret = lttng_session_descriptor_serialize(return_descriptor,
1965 &payload);
1966 if (ret) {
1967 ERR("Failed to serialize session descriptor in reply to \"create session\" command");
1968 lttng_session_descriptor_destroy(return_descriptor);
1969 ret = LTTNG_ERR_NOMEM;
1970 goto error;
1971 }
1972 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, payload.data,
1973 payload.size);
1974 if (ret) {
1975 lttng_session_descriptor_destroy(return_descriptor);
1976 ret = LTTNG_ERR_NOMEM;
1977 goto error;
1978 }
1979 lttng_dynamic_buffer_reset(&payload);
1980 lttng_session_descriptor_destroy(return_descriptor);
1981 ret = LTTNG_OK;
1982 break;
1983 }
1984 case LTTNG_SAVE_SESSION:
1985 {
1986 ret = cmd_save_sessions(&cmd_ctx->lsm->u.save_session.attr,
1987 &cmd_ctx->creds);
1988 break;
1989 }
1990 case LTTNG_SET_SESSION_SHM_PATH:
1991 {
1992 ret = cmd_set_session_shm_path(cmd_ctx->session,
1993 cmd_ctx->lsm->u.set_shm_path.shm_path);
1994 break;
1995 }
1996 case LTTNG_REGENERATE_METADATA:
1997 {
1998 ret = cmd_regenerate_metadata(cmd_ctx->session);
1999 break;
2000 }
2001 case LTTNG_REGENERATE_STATEDUMP:
2002 {
2003 ret = cmd_regenerate_statedump(cmd_ctx->session);
2004 break;
2005 }
2006 case LTTNG_REGISTER_TRIGGER:
2007 {
2008 ret = cmd_register_trigger(cmd_ctx, *sock,
2009 notification_thread_handle);
2010 break;
2011 }
2012 case LTTNG_UNREGISTER_TRIGGER:
2013 {
2014 ret = cmd_unregister_trigger(cmd_ctx, *sock,
2015 notification_thread_handle);
2016 break;
2017 }
2018 case LTTNG_ROTATE_SESSION:
2019 {
2020 struct lttng_rotate_session_return rotate_return;
2021
2022 DBG("Client rotate session \"%s\"", cmd_ctx->session->name);
2023
2024 memset(&rotate_return, 0, sizeof(rotate_return));
2025 if (cmd_ctx->session->kernel_session && !check_rotate_compatible()) {
2026 DBG("Kernel tracer version is not compatible with the rotation feature");
2027 ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
2028 goto error;
2029 }
2030
2031 ret = cmd_rotate_session(cmd_ctx->session, &rotate_return,
2032 false,
2033 LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED);
2034 if (ret < 0) {
2035 ret = -ret;
2036 goto error;
2037 }
2038
2039 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &rotate_return,
2040 sizeof(rotate_return));
2041 if (ret < 0) {
2042 ret = -ret;
2043 goto error;
2044 }
2045
2046 ret = LTTNG_OK;
2047 break;
2048 }
2049 case LTTNG_ROTATION_GET_INFO:
2050 {
2051 struct lttng_rotation_get_info_return get_info_return;
2052
2053 memset(&get_info_return, 0, sizeof(get_info_return));
2054 ret = cmd_rotate_get_info(cmd_ctx->session, &get_info_return,
2055 cmd_ctx->lsm->u.get_rotation_info.rotation_id);
2056 if (ret < 0) {
2057 ret = -ret;
2058 goto error;
2059 }
2060
2061 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &get_info_return,
2062 sizeof(get_info_return));
2063 if (ret < 0) {
2064 ret = -ret;
2065 goto error;
2066 }
2067
2068 ret = LTTNG_OK;
2069 break;
2070 }
2071 case LTTNG_ROTATION_SET_SCHEDULE:
2072 {
2073 bool set_schedule;
2074 enum lttng_rotation_schedule_type schedule_type;
2075 uint64_t value;
2076
2077 if (cmd_ctx->session->kernel_session && !check_rotate_compatible()) {
2078 DBG("Kernel tracer version does not support session rotations");
2079 ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
2080 goto error;
2081 }
2082
2083 set_schedule = cmd_ctx->lsm->u.rotation_set_schedule.set == 1;
2084 schedule_type = (enum lttng_rotation_schedule_type) cmd_ctx->lsm->u.rotation_set_schedule.type;
2085 value = cmd_ctx->lsm->u.rotation_set_schedule.value;
2086
2087 ret = cmd_rotation_set_schedule(cmd_ctx->session,
2088 set_schedule,
2089 schedule_type,
2090 value,
2091 notification_thread_handle);
2092 if (ret != LTTNG_OK) {
2093 goto error;
2094 }
2095
2096 break;
2097 }
2098 case LTTNG_SESSION_LIST_ROTATION_SCHEDULES:
2099 {
2100 struct lttng_session_list_schedules_return schedules = {
2101 .periodic.set = !!cmd_ctx->session->rotate_timer_period,
2102 .periodic.value = cmd_ctx->session->rotate_timer_period,
2103 .size.set = !!cmd_ctx->session->rotate_size,
2104 .size.value = cmd_ctx->session->rotate_size,
2105 };
2106
2107 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &schedules,
2108 sizeof(schedules));
2109 if (ret < 0) {
2110 ret = -ret;
2111 goto error;
2112 }
2113
2114 ret = LTTNG_OK;
2115 break;
2116 }
2117 case LTTNG_CLEAR_SESSION:
2118 {
2119 ret = cmd_clear_session(cmd_ctx->session, sock);
2120 break;
2121 }
2122 default:
2123 ret = LTTNG_ERR_UND;
2124 break;
2125 }
2126
2127 error:
2128 if (cmd_ctx->llm == NULL) {
2129 DBG("Missing llm structure. Allocating one.");
2130 if (setup_lttng_msg_no_cmd_header(cmd_ctx, NULL, 0) < 0) {
2131 goto setup_error;
2132 }
2133 }
2134 /* Set return code */
2135 cmd_ctx->llm->ret_code = ret;
2136 setup_error:
2137 if (cmd_ctx->session) {
2138 session_unlock(cmd_ctx->session);
2139 session_put(cmd_ctx->session);
2140 cmd_ctx->session = NULL;
2141 }
2142 if (need_tracing_session) {
2143 session_unlock_list();
2144 }
2145 init_setup_error:
2146 assert(!rcu_read_ongoing());
2147 return ret;
2148 }
2149
2150 static int create_client_sock(void)
2151 {
2152 int ret, client_sock;
2153 const mode_t old_umask = umask(0);
2154
2155 /* Create client tool unix socket */
2156 client_sock = lttcomm_create_unix_sock(config.client_unix_sock_path.value);
2157 if (client_sock < 0) {
2158 ERR("Create unix sock failed: %s", config.client_unix_sock_path.value);
2159 ret = -1;
2160 goto end;
2161 }
2162
2163 /* Set the cloexec flag */
2164 ret = utils_set_fd_cloexec(client_sock);
2165 if (ret < 0) {
2166 ERR("Unable to set CLOEXEC flag to the client Unix socket (fd: %d). "
2167 "Continuing but note that the consumer daemon will have a "
2168 "reference to this socket on exec()", client_sock);
2169 }
2170
2171 /* File permission MUST be 660 */
2172 ret = chmod(config.client_unix_sock_path.value, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
2173 if (ret < 0) {
2174 ERR("Set file permissions failed: %s",
2175 config.client_unix_sock_path.value);
2176 PERROR("chmod");
2177 (void) lttcomm_close_unix_sock(client_sock);
2178 ret = -1;
2179 goto end;
2180 }
2181 DBG("Created client socket (fd = %i)", client_sock);
2182 ret = client_sock;
2183 end:
2184 umask(old_umask);
2185 return ret;
2186 }
2187
2188 static void cleanup_client_thread(void *data)
2189 {
2190 struct lttng_pipe *quit_pipe = data;
2191
2192 lttng_pipe_destroy(quit_pipe);
2193 }
2194
2195 static void thread_init_cleanup(void *data)
2196 {
2197 set_thread_status(false);
2198 }
2199
2200 /*
2201 * This thread manage all clients request using the unix client socket for
2202 * communication.
2203 */
2204 static void *thread_manage_clients(void *data)
2205 {
2206 int sock = -1, ret, i, pollfd, err = -1;
2207 int sock_error;
2208 uint32_t revents, nb_fd;
2209 struct command_ctx *cmd_ctx = NULL;
2210 struct lttng_poll_event events;
2211 const int client_sock = thread_state.client_sock;
2212 struct lttng_pipe *quit_pipe = data;
2213 const int thread_quit_pipe_fd = lttng_pipe_get_readfd(quit_pipe);
2214
2215 DBG("[thread] Manage client started");
2216
2217 is_root = (getuid() == 0);
2218
2219 pthread_cleanup_push(thread_init_cleanup, NULL);
2220
2221 rcu_register_thread();
2222
2223 health_register(health_sessiond, HEALTH_SESSIOND_TYPE_CMD);
2224
2225 health_code_update();
2226
2227 ret = lttcomm_listen_unix_sock(client_sock);
2228 if (ret < 0) {
2229 goto error_listen;
2230 }
2231
2232 /*
2233 * Pass 2 as size here for the thread quit pipe and client_sock. Nothing
2234 * more will be added to this poll set.
2235 */
2236 ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
2237 if (ret < 0) {
2238 goto error_create_poll;
2239 }
2240
2241 /* Add the application registration socket */
2242 ret = lttng_poll_add(&events, client_sock, LPOLLIN | LPOLLPRI);
2243 if (ret < 0) {
2244 goto error;
2245 }
2246
2247 /* Add thread quit pipe */
2248 ret = lttng_poll_add(&events, thread_quit_pipe_fd, LPOLLIN | LPOLLERR);
2249 if (ret < 0) {
2250 goto error;
2251 }
2252
2253 /* Set state as running. */
2254 set_thread_status(true);
2255 pthread_cleanup_pop(0);
2256
2257 /* This testpoint is after we signal readiness to the parent. */
2258 if (testpoint(sessiond_thread_manage_clients)) {
2259 goto error;
2260 }
2261
2262 if (testpoint(sessiond_thread_manage_clients_before_loop)) {
2263 goto error;
2264 }
2265
2266 health_code_update();
2267
2268 while (1) {
2269 const struct cmd_completion_handler *cmd_completion_handler;
2270
2271 DBG("Accepting client command ...");
2272
2273 /* Inifinite blocking call, waiting for transmission */
2274 restart:
2275 health_poll_entry();
2276 ret = lttng_poll_wait(&events, -1);
2277 health_poll_exit();
2278 if (ret < 0) {
2279 /*
2280 * Restart interrupted system call.
2281 */
2282 if (errno == EINTR) {
2283 goto restart;
2284 }
2285 goto error;
2286 }
2287
2288 nb_fd = ret;
2289
2290 for (i = 0; i < nb_fd; i++) {
2291 revents = LTTNG_POLL_GETEV(&events, i);
2292 pollfd = LTTNG_POLL_GETFD(&events, i);
2293
2294 health_code_update();
2295
2296 if (pollfd == thread_quit_pipe_fd) {
2297 err = 0;
2298 goto exit;
2299 } else {
2300 /* Event on the registration socket */
2301 if (revents & LPOLLIN) {
2302 continue;
2303 } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
2304 ERR("Client socket poll error");
2305 goto error;
2306 } else {
2307 ERR("Unexpected poll events %u for sock %d", revents, pollfd);
2308 goto error;
2309 }
2310 }
2311 }
2312
2313 DBG("Wait for client response");
2314
2315 health_code_update();
2316
2317 sock = lttcomm_accept_unix_sock(client_sock);
2318 if (sock < 0) {
2319 goto error;
2320 }
2321
2322 /*
2323 * Set the CLOEXEC flag. Return code is useless because either way, the
2324 * show must go on.
2325 */
2326 (void) utils_set_fd_cloexec(sock);
2327
2328 /* Set socket option for credentials retrieval */
2329 ret = lttcomm_setsockopt_creds_unix_sock(sock);
2330 if (ret < 0) {
2331 goto error;
2332 }
2333
2334 /* Allocate context command to process the client request */
2335 cmd_ctx = zmalloc(sizeof(struct command_ctx));
2336 if (cmd_ctx == NULL) {
2337 PERROR("zmalloc cmd_ctx");
2338 goto error;
2339 }
2340
2341 /* Allocate data buffer for reception */
2342 cmd_ctx->lsm = zmalloc(sizeof(struct lttcomm_session_msg));
2343 if (cmd_ctx->lsm == NULL) {
2344 PERROR("zmalloc cmd_ctx->lsm");
2345 goto error;
2346 }
2347
2348 cmd_ctx->llm = NULL;
2349 cmd_ctx->session = NULL;
2350
2351 health_code_update();
2352
2353 /*
2354 * Data is received from the lttng client. The struct
2355 * lttcomm_session_msg (lsm) contains the command and data request of
2356 * the client.
2357 */
2358 DBG("Receiving data from client ...");
2359 ret = lttcomm_recv_creds_unix_sock(sock, cmd_ctx->lsm,
2360 sizeof(struct lttcomm_session_msg), &cmd_ctx->creds);
2361 if (ret <= 0) {
2362 DBG("Nothing recv() from client... continuing");
2363 ret = close(sock);
2364 if (ret) {
2365 PERROR("close");
2366 }
2367 sock = -1;
2368 clean_command_ctx(&cmd_ctx);
2369 continue;
2370 }
2371
2372 health_code_update();
2373
2374 // TODO: Validate cmd_ctx including sanity check for
2375 // security purpose.
2376
2377 rcu_thread_online();
2378 /*
2379 * This function dispatch the work to the kernel or userspace tracer
2380 * libs and fill the lttcomm_lttng_msg data structure of all the needed
2381 * informations for the client. The command context struct contains
2382 * everything this function may needs.
2383 */
2384 ret = process_client_msg(cmd_ctx, &sock, &sock_error);
2385 rcu_thread_offline();
2386 if (ret < 0) {
2387 if (sock >= 0) {
2388 ret = close(sock);
2389 if (ret) {
2390 PERROR("close");
2391 }
2392 }
2393 sock = -1;
2394 /*
2395 * TODO: Inform client somehow of the fatal error. At
2396 * this point, ret < 0 means that a zmalloc failed
2397 * (ENOMEM). Error detected but still accept
2398 * command, unless a socket error has been
2399 * detected.
2400 */
2401 clean_command_ctx(&cmd_ctx);
2402 continue;
2403 }
2404
2405 cmd_completion_handler = cmd_pop_completion_handler();
2406 if (cmd_completion_handler) {
2407 enum lttng_error_code completion_code;
2408
2409 completion_code = cmd_completion_handler->run(
2410 cmd_completion_handler->data);
2411 if (completion_code != LTTNG_OK) {
2412 clean_command_ctx(&cmd_ctx);
2413 continue;
2414 }
2415 }
2416
2417 health_code_update();
2418
2419 if (sock >= 0) {
2420 DBG("Sending response (size: %d, retcode: %s (%d))",
2421 cmd_ctx->lttng_msg_size,
2422 lttng_strerror(-cmd_ctx->llm->ret_code),
2423 cmd_ctx->llm->ret_code);
2424 ret = send_unix_sock(sock, cmd_ctx->llm,
2425 cmd_ctx->lttng_msg_size);
2426 if (ret < 0) {
2427 ERR("Failed to send data back to client");
2428 }
2429
2430 /* End of transmission */
2431 ret = close(sock);
2432 if (ret) {
2433 PERROR("close");
2434 }
2435 }
2436 sock = -1;
2437
2438 clean_command_ctx(&cmd_ctx);
2439
2440 health_code_update();
2441 }
2442
2443 exit:
2444 error:
2445 if (sock >= 0) {
2446 ret = close(sock);
2447 if (ret) {
2448 PERROR("close");
2449 }
2450 }
2451
2452 lttng_poll_clean(&events);
2453 clean_command_ctx(&cmd_ctx);
2454
2455 error_listen:
2456 error_create_poll:
2457 unlink(config.client_unix_sock_path.value);
2458 ret = close(client_sock);
2459 if (ret) {
2460 PERROR("close");
2461 }
2462
2463 if (err) {
2464 health_error();
2465 ERR("Health error occurred in %s", __func__);
2466 }
2467
2468 health_unregister(health_sessiond);
2469
2470 DBG("Client thread dying");
2471
2472 rcu_unregister_thread();
2473 return NULL;
2474 }
2475
2476 static
2477 bool shutdown_client_thread(void *thread_data)
2478 {
2479 struct lttng_pipe *client_quit_pipe = thread_data;
2480 const int write_fd = lttng_pipe_get_writefd(client_quit_pipe);
2481
2482 return notify_thread_pipe(write_fd) == 1;
2483 }
2484
2485 struct lttng_thread *launch_client_thread(void)
2486 {
2487 bool thread_running;
2488 struct lttng_pipe *client_quit_pipe;
2489 struct lttng_thread *thread = NULL;
2490 int client_sock_fd = -1;
2491
2492 sem_init(&thread_state.ready, 0, 0);
2493 client_quit_pipe = lttng_pipe_open(FD_CLOEXEC);
2494 if (!client_quit_pipe) {
2495 goto error;
2496 }
2497
2498 client_sock_fd = create_client_sock();
2499 if (client_sock_fd < 0) {
2500 goto error;
2501 }
2502
2503 thread_state.client_sock = client_sock_fd;
2504 thread = lttng_thread_create("Client management",
2505 thread_manage_clients,
2506 shutdown_client_thread,
2507 cleanup_client_thread,
2508 client_quit_pipe);
2509 if (!thread) {
2510 goto error;
2511 }
2512 /* The client thread now owns the client sock fd and the quit pipe. */
2513 client_sock_fd = -1;
2514 client_quit_pipe = NULL;
2515
2516 /*
2517 * This thread is part of the threads that need to be fully
2518 * initialized before the session daemon is marked as "ready".
2519 */
2520 thread_running = wait_thread_status();
2521 if (!thread_running) {
2522 goto error;
2523 }
2524 return thread;
2525 error:
2526 if (client_sock_fd >= 0) {
2527 if (close(client_sock_fd)) {
2528 PERROR("Failed to close client socket");
2529 }
2530 }
2531 lttng_thread_put(thread);
2532 cleanup_client_thread(client_quit_pipe);
2533 return NULL;
2534 }
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