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[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/compat/socket.h"
12 #include "common/dynamic-array.h"
13 #include "common/dynamic-buffer.h"
14 #include "common/fd-handle.h"
15 #include "common/payload-view.h"
16 #include "common/payload.h"
17 #include "common/sessiond-comm/sessiond-comm.h"
18 #include "lttng/lttng-error.h"
19 #include "lttng/tracker.h"
20 #include <common/compat/getenv.h>
21 #include <common/tracker.h>
22 #include <common/unix.h>
23 #include <common/utils.h>
24 #include <lttng/error-query-internal.h>
25 #include <lttng/event-internal.h>
26 #include <lttng/session-descriptor-internal.h>
27 #include <lttng/session-internal.h>
28 #include <lttng/userspace-probe-internal.h>
29 #include <pthread.h>
30 #include <signal.h>
31 #include <stddef.h>
32 #include <sys/stat.h>
33 #include <unistd.h>
34
35 #include "agent-thread.h"
36 #include "clear.h"
37 #include "client.h"
38 #include "cmd.h"
39 #include "health-sessiond.h"
40 #include "kernel.h"
41 #include "lttng-sessiond.h"
42 #include "manage-consumer.h"
43 #include "save.h"
44 #include "testpoint.h"
45 #include "utils.h"
46
47 static bool is_root;
48
49 static struct thread_state {
50 sem_t ready;
51 bool running;
52 int client_sock;
53 } thread_state;
54
55 static void set_thread_status(bool running)
56 {
57 DBG("Marking client thread's state as %s", running ? "running" : "error");
58 thread_state.running = running;
59 sem_post(&thread_state.ready);
60 }
61
62 static bool wait_thread_status(void)
63 {
64 DBG("Waiting for client thread to be ready");
65 sem_wait(&thread_state.ready);
66 if (thread_state.running) {
67 DBG("Client thread is ready");
68 } else {
69 ERR("Initialization of client thread failed");
70 }
71
72 return thread_state.running;
73 }
74
75 /*
76 * Setup the outgoing data buffer for the response (llm) by allocating the
77 * right amount of memory and copying the original information from the lsm
78 * structure.
79 *
80 * Return 0 on success, negative value on error.
81 */
82 static int setup_lttng_msg(struct command_ctx *cmd_ctx,
83 const void *payload_buf, size_t payload_len,
84 const void *cmd_header_buf, size_t cmd_header_len)
85 {
86 int ret = 0;
87 const size_t header_len = sizeof(struct lttcomm_lttng_msg);
88 const size_t total_msg_size = header_len + cmd_header_len + payload_len;
89 const struct lttcomm_lttng_msg llm = {
90 .cmd_type = cmd_ctx->lsm.cmd_type,
91 .pid = cmd_ctx->lsm.domain.attr.pid,
92 .cmd_header_size = cmd_header_len,
93 .data_size = payload_len,
94 };
95
96 ret = lttng_dynamic_buffer_set_size(&cmd_ctx->reply_payload.buffer, 0);
97 if (ret) {
98 goto end;
99 }
100
101 lttng_dynamic_pointer_array_clear(&cmd_ctx->reply_payload._fd_handles);
102
103 cmd_ctx->lttng_msg_size = total_msg_size;
104
105 /* Append reply header. */
106 ret = lttng_dynamic_buffer_append(
107 &cmd_ctx->reply_payload.buffer, &llm, sizeof(llm));
108 if (ret) {
109 goto end;
110 }
111
112 /* Append command header. */
113 if (cmd_header_len) {
114 ret = lttng_dynamic_buffer_append(
115 &cmd_ctx->reply_payload.buffer, cmd_header_buf,
116 cmd_header_len);
117 if (ret) {
118 goto end;
119 }
120 }
121
122 /* Append payload. */
123 if (payload_len) {
124 ret = lttng_dynamic_buffer_append(
125 &cmd_ctx->reply_payload.buffer, payload_buf,
126 payload_len);
127 if (ret) {
128 goto end;
129 }
130 }
131
132 end:
133 return ret;
134 }
135
136 static int setup_empty_lttng_msg(struct command_ctx *cmd_ctx)
137 {
138 int ret;
139 const struct lttcomm_lttng_msg llm = {};
140
141 ret = lttng_dynamic_buffer_set_size(&cmd_ctx->reply_payload.buffer, 0);
142 if (ret) {
143 goto end;
144 }
145
146 /* Append place-holder reply header. */
147 ret = lttng_dynamic_buffer_append(
148 &cmd_ctx->reply_payload.buffer, &llm, sizeof(llm));
149 if (ret) {
150 goto end;
151 }
152
153 cmd_ctx->lttng_msg_size = sizeof(llm);
154 end:
155 return ret;
156 }
157
158 static void update_lttng_msg(struct command_ctx *cmd_ctx, size_t cmd_header_len,
159 size_t payload_len)
160 {
161 const size_t header_len = sizeof(struct lttcomm_lttng_msg);
162 const size_t total_msg_size = header_len + cmd_header_len + payload_len;
163 const struct lttcomm_lttng_msg llm = {
164 .cmd_type = cmd_ctx->lsm.cmd_type,
165 .pid = cmd_ctx->lsm.domain.attr.pid,
166 .cmd_header_size = cmd_header_len,
167 .data_size = payload_len,
168 };
169 struct lttcomm_lttng_msg *p_llm;
170
171 LTTNG_ASSERT(cmd_ctx->reply_payload.buffer.size >= sizeof(llm));
172
173 p_llm = (typeof(p_llm)) cmd_ctx->reply_payload.buffer.data;
174
175 /* Update existing header. */
176 memcpy(p_llm, &llm, sizeof(llm));
177
178 cmd_ctx->lttng_msg_size = total_msg_size;
179 }
180
181 /*
182 * Start the thread_manage_consumer. This must be done after a lttng-consumerd
183 * exec or it will fail.
184 */
185 static int spawn_consumer_thread(struct consumer_data *consumer_data)
186 {
187 return launch_consumer_management_thread(consumer_data) ? 0 : -1;
188 }
189
190 /*
191 * Fork and exec a consumer daemon (consumerd).
192 *
193 * Return pid if successful else -1.
194 */
195 static pid_t spawn_consumerd(struct consumer_data *consumer_data)
196 {
197 int ret;
198 pid_t pid;
199 const char *consumer_to_use;
200 const char *verbosity;
201 struct stat st;
202
203 DBG("Spawning consumerd");
204
205 pid = fork();
206 if (pid == 0) {
207 /*
208 * Exec consumerd.
209 */
210 if (the_config.verbose_consumer) {
211 verbosity = "--verbose";
212 } else if (lttng_opt_quiet) {
213 verbosity = "--quiet";
214 } else {
215 verbosity = "";
216 }
217
218 switch (consumer_data->type) {
219 case LTTNG_CONSUMER_KERNEL:
220 /*
221 * Find out which consumerd to execute. We will first try the
222 * 64-bit path, then the sessiond's installation directory, and
223 * fallback on the 32-bit one,
224 */
225 DBG3("Looking for a kernel consumer at these locations:");
226 DBG3(" 1) %s", the_config.consumerd64_bin_path.value ? : "NULL");
227 DBG3(" 2) %s/%s", INSTALL_BIN_PATH, DEFAULT_CONSUMERD_FILE);
228 DBG3(" 3) %s", the_config.consumerd32_bin_path.value ? : "NULL");
229 if (stat(the_config.consumerd64_bin_path.value, &st) == 0) {
230 DBG3("Found location #1");
231 consumer_to_use = the_config.consumerd64_bin_path.value;
232 } else if (stat(INSTALL_BIN_PATH "/" DEFAULT_CONSUMERD_FILE, &st) == 0) {
233 DBG3("Found location #2");
234 consumer_to_use = INSTALL_BIN_PATH "/" DEFAULT_CONSUMERD_FILE;
235 } else if (the_config.consumerd32_bin_path.value &&
236 stat(the_config.consumerd32_bin_path.value, &st) == 0) {
237 DBG3("Found location #3");
238 consumer_to_use = the_config.consumerd32_bin_path.value;
239 } else {
240 DBG("Could not find any valid consumerd executable");
241 ret = -EINVAL;
242 goto error;
243 }
244 DBG("Using kernel consumer at: %s", consumer_to_use);
245 (void) execl(consumer_to_use, "lttng-consumerd",
246 verbosity, "-k", "--consumerd-cmd-sock",
247 consumer_data->cmd_unix_sock_path,
248 "--consumerd-err-sock",
249 consumer_data->err_unix_sock_path,
250 "--group",
251 the_config.tracing_group_name.value,
252 NULL);
253 break;
254 case LTTNG_CONSUMER64_UST:
255 {
256 if (the_config.consumerd64_lib_dir.value) {
257 const char *tmp;
258 size_t tmplen;
259 char *tmpnew;
260
261 tmp = lttng_secure_getenv("LD_LIBRARY_PATH");
262 if (!tmp) {
263 tmp = "";
264 }
265 tmplen = strlen(the_config.consumerd64_lib_dir.value) + 1 /* : */ + strlen(tmp);
266 tmpnew = zmalloc(tmplen + 1 /* \0 */);
267 if (!tmpnew) {
268 ret = -ENOMEM;
269 goto error;
270 }
271 strcat(tmpnew, the_config.consumerd64_lib_dir.value);
272 if (tmp[0] != '\0') {
273 strcat(tmpnew, ":");
274 strcat(tmpnew, tmp);
275 }
276 ret = setenv("LD_LIBRARY_PATH", tmpnew, 1);
277 free(tmpnew);
278 if (ret) {
279 ret = -errno;
280 goto error;
281 }
282 }
283 DBG("Using 64-bit UST consumer at: %s",
284 the_config.consumerd64_bin_path.value);
285 (void) execl(the_config.consumerd64_bin_path.value,
286 "lttng-consumerd", verbosity, "-u",
287 "--consumerd-cmd-sock",
288 consumer_data->cmd_unix_sock_path,
289 "--consumerd-err-sock",
290 consumer_data->err_unix_sock_path,
291 "--group",
292 the_config.tracing_group_name.value,
293 NULL);
294 break;
295 }
296 case LTTNG_CONSUMER32_UST:
297 {
298 if (the_config.consumerd32_lib_dir.value) {
299 const char *tmp;
300 size_t tmplen;
301 char *tmpnew;
302
303 tmp = lttng_secure_getenv("LD_LIBRARY_PATH");
304 if (!tmp) {
305 tmp = "";
306 }
307 tmplen = strlen(the_config.consumerd32_lib_dir.value) + 1 /* : */ + strlen(tmp);
308 tmpnew = zmalloc(tmplen + 1 /* \0 */);
309 if (!tmpnew) {
310 ret = -ENOMEM;
311 goto error;
312 }
313 strcat(tmpnew, the_config.consumerd32_lib_dir.value);
314 if (tmp[0] != '\0') {
315 strcat(tmpnew, ":");
316 strcat(tmpnew, tmp);
317 }
318 ret = setenv("LD_LIBRARY_PATH", tmpnew, 1);
319 free(tmpnew);
320 if (ret) {
321 ret = -errno;
322 goto error;
323 }
324 }
325 DBG("Using 32-bit UST consumer at: %s",
326 the_config.consumerd32_bin_path.value);
327 (void) execl(the_config.consumerd32_bin_path.value,
328 "lttng-consumerd", verbosity, "-u",
329 "--consumerd-cmd-sock",
330 consumer_data->cmd_unix_sock_path,
331 "--consumerd-err-sock",
332 consumer_data->err_unix_sock_path,
333 "--group",
334 the_config.tracing_group_name.value,
335 NULL);
336 break;
337 }
338 default:
339 ERR("unknown consumer type");
340 errno = 0;
341 }
342 if (errno != 0) {
343 PERROR("Consumer execl()");
344 }
345 /* Reaching this point, we got a failure on our execl(). */
346 exit(EXIT_FAILURE);
347 } else if (pid > 0) {
348 ret = pid;
349 } else {
350 PERROR("start consumer fork");
351 ret = -errno;
352 }
353 error:
354 return ret;
355 }
356
357 /*
358 * Spawn the consumerd daemon and session daemon thread.
359 */
360 static int start_consumerd(struct consumer_data *consumer_data)
361 {
362 int ret;
363
364 /*
365 * Set the listen() state on the socket since there is a possible race
366 * between the exec() of the consumer daemon and this call if place in the
367 * consumer thread. See bug #366 for more details.
368 */
369 ret = lttcomm_listen_unix_sock(consumer_data->err_sock);
370 if (ret < 0) {
371 goto error;
372 }
373
374 pthread_mutex_lock(&consumer_data->pid_mutex);
375 if (consumer_data->pid != 0) {
376 pthread_mutex_unlock(&consumer_data->pid_mutex);
377 goto end;
378 }
379
380 ret = spawn_consumerd(consumer_data);
381 if (ret < 0) {
382 ERR("Spawning consumerd failed");
383 pthread_mutex_unlock(&consumer_data->pid_mutex);
384 goto error;
385 }
386
387 /* Setting up the consumer_data pid */
388 consumer_data->pid = ret;
389 DBG2("Consumer pid %d", consumer_data->pid);
390 pthread_mutex_unlock(&consumer_data->pid_mutex);
391
392 DBG2("Spawning consumer control thread");
393 ret = spawn_consumer_thread(consumer_data);
394 if (ret < 0) {
395 ERR("Fatal error spawning consumer control thread");
396 goto error;
397 }
398
399 end:
400 return 0;
401
402 error:
403 /* Cleanup already created sockets on error. */
404 if (consumer_data->err_sock >= 0) {
405 int err;
406
407 err = close(consumer_data->err_sock);
408 if (err < 0) {
409 PERROR("close consumer data error socket");
410 }
411 }
412 return ret;
413 }
414
415 /*
416 * Copy consumer output from the tracing session to the domain session. The
417 * function also applies the right modification on a per domain basis for the
418 * trace files destination directory.
419 *
420 * Should *NOT* be called with RCU read-side lock held.
421 */
422 static int copy_session_consumer(int domain, struct ltt_session *session)
423 {
424 int ret;
425 const char *dir_name;
426 struct consumer_output *consumer;
427
428 LTTNG_ASSERT(session);
429 LTTNG_ASSERT(session->consumer);
430
431 switch (domain) {
432 case LTTNG_DOMAIN_KERNEL:
433 DBG3("Copying tracing session consumer output in kernel session");
434 /*
435 * XXX: We should audit the session creation and what this function
436 * does "extra" in order to avoid a destroy since this function is used
437 * in the domain session creation (kernel and ust) only. Same for UST
438 * domain.
439 */
440 if (session->kernel_session->consumer) {
441 consumer_output_put(session->kernel_session->consumer);
442 }
443 session->kernel_session->consumer =
444 consumer_copy_output(session->consumer);
445 /* Ease our life a bit for the next part */
446 consumer = session->kernel_session->consumer;
447 dir_name = DEFAULT_KERNEL_TRACE_DIR;
448 break;
449 case LTTNG_DOMAIN_JUL:
450 case LTTNG_DOMAIN_LOG4J:
451 case LTTNG_DOMAIN_PYTHON:
452 case LTTNG_DOMAIN_UST:
453 DBG3("Copying tracing session consumer output in UST session");
454 if (session->ust_session->consumer) {
455 consumer_output_put(session->ust_session->consumer);
456 }
457 session->ust_session->consumer =
458 consumer_copy_output(session->consumer);
459 /* Ease our life a bit for the next part */
460 consumer = session->ust_session->consumer;
461 dir_name = DEFAULT_UST_TRACE_DIR;
462 break;
463 default:
464 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
465 goto error;
466 }
467
468 /* Append correct directory to subdir */
469 ret = lttng_strncpy(consumer->domain_subdir, dir_name,
470 sizeof(consumer->domain_subdir));
471 if (ret) {
472 ret = LTTNG_ERR_UNK;
473 goto error;
474 }
475 DBG3("Copy session consumer subdir %s", consumer->domain_subdir);
476 ret = LTTNG_OK;
477
478 error:
479 return ret;
480 }
481
482 /*
483 * Create an UST session and add it to the session ust list.
484 *
485 * Should *NOT* be called with RCU read-side lock held.
486 */
487 static int create_ust_session(struct ltt_session *session,
488 const struct lttng_domain *domain)
489 {
490 int ret;
491 struct ltt_ust_session *lus = NULL;
492
493 LTTNG_ASSERT(session);
494 LTTNG_ASSERT(domain);
495 LTTNG_ASSERT(session->consumer);
496
497 switch (domain->type) {
498 case LTTNG_DOMAIN_JUL:
499 case LTTNG_DOMAIN_LOG4J:
500 case LTTNG_DOMAIN_PYTHON:
501 case LTTNG_DOMAIN_UST:
502 break;
503 default:
504 ERR("Unknown UST domain on create session %d", domain->type);
505 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
506 goto error;
507 }
508
509 DBG("Creating UST session");
510
511 lus = trace_ust_create_session(session->id);
512 if (lus == NULL) {
513 ret = LTTNG_ERR_UST_SESS_FAIL;
514 goto error;
515 }
516
517 lus->uid = session->uid;
518 lus->gid = session->gid;
519 lus->output_traces = session->output_traces;
520 lus->snapshot_mode = session->snapshot_mode;
521 lus->live_timer_interval = session->live_timer;
522 session->ust_session = lus;
523 if (session->shm_path[0]) {
524 strncpy(lus->root_shm_path, session->shm_path,
525 sizeof(lus->root_shm_path));
526 lus->root_shm_path[sizeof(lus->root_shm_path) - 1] = '\0';
527 strncpy(lus->shm_path, session->shm_path,
528 sizeof(lus->shm_path));
529 lus->shm_path[sizeof(lus->shm_path) - 1] = '\0';
530 strncat(lus->shm_path, "/ust",
531 sizeof(lus->shm_path) - strlen(lus->shm_path) - 1);
532 }
533 /* Copy session output to the newly created UST session */
534 ret = copy_session_consumer(domain->type, session);
535 if (ret != LTTNG_OK) {
536 goto error;
537 }
538
539 return LTTNG_OK;
540
541 error:
542 free(lus);
543 session->ust_session = NULL;
544 return ret;
545 }
546
547 /*
548 * Create a kernel tracer session then create the default channel.
549 */
550 static int create_kernel_session(struct ltt_session *session)
551 {
552 int ret;
553
554 DBG("Creating kernel session");
555
556 ret = kernel_create_session(session);
557 if (ret < 0) {
558 ret = LTTNG_ERR_KERN_SESS_FAIL;
559 goto error_create;
560 }
561
562 /* Code flow safety */
563 LTTNG_ASSERT(session->kernel_session);
564
565 /* Copy session output to the newly created Kernel session */
566 ret = copy_session_consumer(LTTNG_DOMAIN_KERNEL, session);
567 if (ret != LTTNG_OK) {
568 goto error;
569 }
570
571 session->kernel_session->uid = session->uid;
572 session->kernel_session->gid = session->gid;
573 session->kernel_session->output_traces = session->output_traces;
574 session->kernel_session->snapshot_mode = session->snapshot_mode;
575 session->kernel_session->is_live_session = session->live_timer != 0;
576
577 return LTTNG_OK;
578
579 error:
580 trace_kernel_destroy_session(session->kernel_session);
581 session->kernel_session = NULL;
582 error_create:
583 return ret;
584 }
585
586 /*
587 * Count number of session permitted by uid/gid.
588 */
589 static unsigned int lttng_sessions_count(uid_t uid, gid_t gid)
590 {
591 unsigned int i = 0;
592 struct ltt_session *session;
593 const struct ltt_session_list *session_list = session_get_list();
594
595 DBG("Counting number of available session for UID %d", uid);
596 cds_list_for_each_entry(session, &session_list->head, list) {
597 if (!session_get(session)) {
598 continue;
599 }
600 session_lock(session);
601 /* Only count the sessions the user can control. */
602 if (session_access_ok(session, uid) &&
603 !session->destroyed) {
604 i++;
605 }
606 session_unlock(session);
607 session_put(session);
608 }
609 return i;
610 }
611
612 static int receive_userspace_probe(struct command_ctx *cmd_ctx, int sock,
613 int *sock_error, struct lttng_event *event)
614 {
615 int fd = -1, ret;
616 struct lttng_userspace_probe_location *probe_location;
617 struct lttng_payload probe_location_payload;
618 struct fd_handle *handle = NULL;
619
620 /*
621 * Create a payload to store the serialized version of the probe
622 * location.
623 */
624 lttng_payload_init(&probe_location_payload);
625
626 ret = lttng_dynamic_buffer_set_size(&probe_location_payload.buffer,
627 cmd_ctx->lsm.u.enable.userspace_probe_location_len);
628 if (ret) {
629 ret = LTTNG_ERR_NOMEM;
630 goto error;
631 }
632
633 /*
634 * Receive the probe location.
635 */
636 ret = lttcomm_recv_unix_sock(sock, probe_location_payload.buffer.data,
637 probe_location_payload.buffer.size);
638 if (ret <= 0) {
639 DBG("Nothing recv() from client var len data... continuing");
640 *sock_error = 1;
641 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
642 goto error;
643 }
644
645 /*
646 * Receive the file descriptor to the target binary from the client.
647 */
648 DBG("Receiving userspace probe target FD from client ...");
649 ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1);
650 if (ret <= 0) {
651 DBG("Nothing recv() from client userspace probe fd... continuing");
652 *sock_error = 1;
653 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
654 goto error;
655 }
656
657 handle = fd_handle_create(fd);
658 if (!handle) {
659 ret = LTTNG_ERR_NOMEM;
660 goto error;
661 }
662
663 /* Transferred to the handle. */
664 fd = -1;
665
666 ret = lttng_payload_push_fd_handle(&probe_location_payload, handle);
667 if (ret) {
668 ERR("Failed to add userspace probe file descriptor to payload");
669 ret = LTTNG_ERR_NOMEM;
670 goto error;
671 }
672
673 fd_handle_put(handle);
674 handle = NULL;
675
676 {
677 struct lttng_payload_view view = lttng_payload_view_from_payload(
678 &probe_location_payload, 0, -1);
679
680 /* Extract the probe location from the serialized version. */
681 ret = lttng_userspace_probe_location_create_from_payload(
682 &view, &probe_location);
683 }
684 if (ret < 0) {
685 WARN("Failed to create a userspace probe location from the received buffer");
686 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
687 goto error;
688 }
689
690 /* Attach the probe location to the event. */
691 ret = lttng_event_set_userspace_probe_location(event, probe_location);
692 if (ret) {
693 ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
694 goto error;
695 }
696
697 error:
698 if (fd >= 0) {
699 if (close(fd)) {
700 PERROR("Failed to close userspace probe location binary fd");
701 }
702 }
703
704 fd_handle_put(handle);
705 lttng_payload_reset(&probe_location_payload);
706 return ret;
707 }
708
709 static enum lttng_error_code receive_lttng_trigger(struct command_ctx *cmd_ctx,
710 int sock,
711 int *sock_error,
712 struct lttng_trigger **_trigger)
713 {
714 int ret;
715 size_t trigger_len;
716 ssize_t sock_recv_len;
717 enum lttng_error_code ret_code;
718 struct lttng_payload trigger_payload;
719 struct lttng_trigger *trigger = NULL;
720
721 lttng_payload_init(&trigger_payload);
722 trigger_len = (size_t) cmd_ctx->lsm.u.trigger.length;
723 ret = lttng_dynamic_buffer_set_size(
724 &trigger_payload.buffer, trigger_len);
725 if (ret) {
726 ret_code = LTTNG_ERR_NOMEM;
727 goto end;
728 }
729
730 sock_recv_len = lttcomm_recv_unix_sock(
731 sock, trigger_payload.buffer.data, trigger_len);
732 if (sock_recv_len < 0 || sock_recv_len != trigger_len) {
733 ERR("Failed to receive trigger in command payload");
734 *sock_error = 1;
735 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
736 goto end;
737 }
738
739 /* Receive fds, if any. */
740 if (cmd_ctx->lsm.fd_count > 0) {
741 sock_recv_len = lttcomm_recv_payload_fds_unix_sock(
742 sock, cmd_ctx->lsm.fd_count, &trigger_payload);
743 if (sock_recv_len > 0 &&
744 sock_recv_len != cmd_ctx->lsm.fd_count * sizeof(int)) {
745 ERR("Failed to receive all file descriptors for trigger in command payload: expected fd count = %u, ret = %d",
746 cmd_ctx->lsm.fd_count, (int) ret);
747 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
748 *sock_error = 1;
749 goto end;
750 } else if (sock_recv_len <= 0) {
751 ERR("Failed to receive file descriptors for trigger in command payload: expected fd count = %u, ret = %d",
752 cmd_ctx->lsm.fd_count, (int) ret);
753 ret_code = LTTNG_ERR_FATAL;
754 *sock_error = 1;
755 goto end;
756 }
757 }
758
759 /* Deserialize trigger. */
760 {
761 struct lttng_payload_view view =
762 lttng_payload_view_from_payload(
763 &trigger_payload, 0, -1);
764
765 if (lttng_trigger_create_from_payload(&view, &trigger) !=
766 trigger_len) {
767 ERR("Invalid trigger received as part of command payload");
768 ret_code = LTTNG_ERR_INVALID_TRIGGER;
769 lttng_trigger_put(trigger);
770 goto end;
771 }
772 }
773
774 *_trigger = trigger;
775 ret_code = LTTNG_OK;
776
777 end:
778 lttng_payload_reset(&trigger_payload);
779 return ret_code;
780 }
781
782 static enum lttng_error_code receive_lttng_error_query(struct command_ctx *cmd_ctx,
783 int sock,
784 int *sock_error,
785 struct lttng_error_query **_query)
786 {
787 int ret;
788 size_t query_len;
789 ssize_t sock_recv_len;
790 enum lttng_error_code ret_code;
791 struct lttng_payload query_payload;
792 struct lttng_error_query *query = NULL;
793
794 lttng_payload_init(&query_payload);
795 query_len = (size_t) cmd_ctx->lsm.u.error_query.length;
796 ret = lttng_dynamic_buffer_set_size(&query_payload.buffer, query_len);
797 if (ret) {
798 ret_code = LTTNG_ERR_NOMEM;
799 goto end;
800 }
801
802 sock_recv_len = lttcomm_recv_unix_sock(
803 sock, query_payload.buffer.data, query_len);
804 if (sock_recv_len < 0 || sock_recv_len != query_len) {
805 ERR("Failed to receive error query in command payload");
806 *sock_error = 1;
807 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
808 goto end;
809 }
810
811 /* Receive fds, if any. */
812 if (cmd_ctx->lsm.fd_count > 0) {
813 sock_recv_len = lttcomm_recv_payload_fds_unix_sock(
814 sock, cmd_ctx->lsm.fd_count, &query_payload);
815 if (sock_recv_len > 0 &&
816 sock_recv_len != cmd_ctx->lsm.fd_count * sizeof(int)) {
817 ERR("Failed to receive all file descriptors for error query in command payload: expected fd count = %u, ret = %d",
818 cmd_ctx->lsm.fd_count, (int) ret);
819 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
820 *sock_error = 1;
821 goto end;
822 } else if (sock_recv_len <= 0) {
823 ERR("Failed to receive file descriptors for error query in command payload: expected fd count = %u, ret = %d",
824 cmd_ctx->lsm.fd_count, (int) ret);
825 ret_code = LTTNG_ERR_FATAL;
826 *sock_error = 1;
827 goto end;
828 }
829 }
830
831 /* Deserialize error query. */
832 {
833 struct lttng_payload_view view =
834 lttng_payload_view_from_payload(
835 &query_payload, 0, -1);
836
837 if (lttng_error_query_create_from_payload(&view, &query) !=
838 query_len) {
839 ERR("Invalid error query received as part of command payload");
840 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
841 goto end;
842 }
843 }
844
845 *_query = query;
846 ret_code = LTTNG_OK;
847
848 end:
849 lttng_payload_reset(&query_payload);
850 return ret_code;
851 }
852
853 /*
854 * Version of setup_lttng_msg() without command header.
855 */
856 static int setup_lttng_msg_no_cmd_header(struct command_ctx *cmd_ctx,
857 void *payload_buf, size_t payload_len)
858 {
859 return setup_lttng_msg(cmd_ctx, payload_buf, payload_len, NULL, 0);
860 }
861
862 /*
863 * Check if the current kernel tracer supports the session rotation feature.
864 * Return 1 if it does, 0 otherwise.
865 */
866 static int check_rotate_compatible(void)
867 {
868 int ret = 1;
869
870 if (the_kernel_tracer_version.major != 2 ||
871 the_kernel_tracer_version.minor < 11) {
872 DBG("Kernel tracer version is not compatible with the rotation feature");
873 ret = 0;
874 }
875
876 return ret;
877 }
878
879 /*
880 * Send data on a unix socket using the liblttsessiondcomm API.
881 *
882 * Return lttcomm error code.
883 */
884 static int send_unix_sock(int sock, struct lttng_payload_view *view)
885 {
886 int ret;
887 const int fd_count = lttng_payload_view_get_fd_handle_count(view);
888
889 /* Check valid length */
890 if (view->buffer.size == 0) {
891 ret = -1;
892 goto end;
893 }
894
895 ret = lttcomm_send_unix_sock(
896 sock, view->buffer.data, view->buffer.size);
897 if (ret < 0) {
898 goto end;
899 }
900
901 if (fd_count > 0) {
902 ret = lttcomm_send_payload_view_fds_unix_sock(sock, view);
903 if (ret < 0) {
904 goto end;
905 }
906 }
907
908 end:
909 return ret;
910 }
911
912 /*
913 * Process the command requested by the lttng client within the command
914 * context structure. This function make sure that the return structure (llm)
915 * is set and ready for transmission before returning.
916 *
917 * Return any error encountered or 0 for success.
918 *
919 * "sock" is only used for special-case var. len data.
920 * A command may assume the ownership of the socket, in which case its value
921 * should be set to -1.
922 *
923 * Should *NOT* be called with RCU read-side lock held.
924 */
925 static int process_client_msg(struct command_ctx *cmd_ctx, int *sock,
926 int *sock_error)
927 {
928 int ret = LTTNG_OK;
929 bool need_tracing_session = true;
930 bool need_domain;
931 bool need_consumerd;
932
933 DBG("Processing client command '%s\' (%d)",
934 lttcomm_sessiond_command_str(cmd_ctx->lsm.cmd_type),
935 cmd_ctx->lsm.cmd_type);
936
937 LTTNG_ASSERT(!rcu_read_ongoing());
938
939 *sock_error = 0;
940
941 switch (cmd_ctx->lsm.cmd_type) {
942 case LTTNG_CREATE_SESSION_EXT:
943 case LTTNG_DESTROY_SESSION:
944 case LTTNG_LIST_SESSIONS:
945 case LTTNG_LIST_DOMAINS:
946 case LTTNG_START_TRACE:
947 case LTTNG_STOP_TRACE:
948 case LTTNG_DATA_PENDING:
949 case LTTNG_SNAPSHOT_ADD_OUTPUT:
950 case LTTNG_SNAPSHOT_DEL_OUTPUT:
951 case LTTNG_SNAPSHOT_LIST_OUTPUT:
952 case LTTNG_SNAPSHOT_RECORD:
953 case LTTNG_SAVE_SESSION:
954 case LTTNG_SET_SESSION_SHM_PATH:
955 case LTTNG_REGENERATE_METADATA:
956 case LTTNG_REGENERATE_STATEDUMP:
957 case LTTNG_ROTATE_SESSION:
958 case LTTNG_ROTATION_GET_INFO:
959 case LTTNG_ROTATION_SET_SCHEDULE:
960 case LTTNG_SESSION_LIST_ROTATION_SCHEDULES:
961 case LTTNG_CLEAR_SESSION:
962 case LTTNG_LIST_TRIGGERS:
963 case LTTNG_EXECUTE_ERROR_QUERY:
964 need_domain = false;
965 break;
966 default:
967 need_domain = true;
968 }
969
970 /* Needs a functioning consumerd? */
971 switch (cmd_ctx->lsm.cmd_type) {
972 case LTTNG_REGISTER_TRIGGER:
973 case LTTNG_UNREGISTER_TRIGGER:
974 case LTTNG_EXECUTE_ERROR_QUERY:
975 need_consumerd = false;
976 break;
977 default:
978 need_consumerd = true;
979 break;
980 }
981
982 if (the_config.no_kernel && need_domain &&
983 cmd_ctx->lsm.domain.type == LTTNG_DOMAIN_KERNEL) {
984 if (!is_root) {
985 ret = LTTNG_ERR_NEED_ROOT_SESSIOND;
986 } else {
987 ret = LTTNG_ERR_KERN_NA;
988 }
989 goto error;
990 }
991
992 /* Deny register consumer if we already have a spawned consumer. */
993 if (cmd_ctx->lsm.cmd_type == LTTNG_REGISTER_CONSUMER) {
994 pthread_mutex_lock(&the_kconsumer_data.pid_mutex);
995 if (the_kconsumer_data.pid > 0) {
996 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
997 pthread_mutex_unlock(&the_kconsumer_data.pid_mutex);
998 goto error;
999 }
1000 pthread_mutex_unlock(&the_kconsumer_data.pid_mutex);
1001 }
1002
1003 /*
1004 * Check for command that don't needs to allocate a returned payload. We do
1005 * this here so we don't have to make the call for no payload at each
1006 * command.
1007 */
1008 switch(cmd_ctx->lsm.cmd_type) {
1009 case LTTNG_LIST_SESSIONS:
1010 case LTTNG_LIST_TRACEPOINTS:
1011 case LTTNG_LIST_TRACEPOINT_FIELDS:
1012 case LTTNG_LIST_DOMAINS:
1013 case LTTNG_LIST_CHANNELS:
1014 case LTTNG_LIST_EVENTS:
1015 case LTTNG_LIST_SYSCALLS:
1016 case LTTNG_SESSION_LIST_ROTATION_SCHEDULES:
1017 case LTTNG_PROCESS_ATTR_TRACKER_GET_POLICY:
1018 case LTTNG_PROCESS_ATTR_TRACKER_GET_INCLUSION_SET:
1019 case LTTNG_DATA_PENDING:
1020 case LTTNG_ROTATE_SESSION:
1021 case LTTNG_ROTATION_GET_INFO:
1022 case LTTNG_REGISTER_TRIGGER:
1023 case LTTNG_LIST_TRIGGERS:
1024 case LTTNG_EXECUTE_ERROR_QUERY:
1025 break;
1026 default:
1027 /* Setup lttng message with no payload */
1028 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, NULL, 0);
1029 if (ret < 0) {
1030 /* This label does not try to unlock the session */
1031 goto init_setup_error;
1032 }
1033 }
1034
1035 /* Commands that DO NOT need a session. */
1036 switch (cmd_ctx->lsm.cmd_type) {
1037 case LTTNG_CREATE_SESSION_EXT:
1038 case LTTNG_LIST_SESSIONS:
1039 case LTTNG_LIST_TRACEPOINTS:
1040 case LTTNG_LIST_SYSCALLS:
1041 case LTTNG_LIST_TRACEPOINT_FIELDS:
1042 case LTTNG_SAVE_SESSION:
1043 case LTTNG_REGISTER_TRIGGER:
1044 case LTTNG_UNREGISTER_TRIGGER:
1045 case LTTNG_LIST_TRIGGERS:
1046 case LTTNG_EXECUTE_ERROR_QUERY:
1047 need_tracing_session = false;
1048 break;
1049 default:
1050 DBG("Getting session %s by name", cmd_ctx->lsm.session.name);
1051 /*
1052 * We keep the session list lock across _all_ commands
1053 * for now, because the per-session lock does not
1054 * handle teardown properly.
1055 */
1056 session_lock_list();
1057 cmd_ctx->session = session_find_by_name(cmd_ctx->lsm.session.name);
1058 if (cmd_ctx->session == NULL) {
1059 ret = LTTNG_ERR_SESS_NOT_FOUND;
1060 goto error;
1061 } else {
1062 /* Acquire lock for the session */
1063 session_lock(cmd_ctx->session);
1064 }
1065 break;
1066 }
1067
1068 /*
1069 * Commands that need a valid session but should NOT create one if none
1070 * exists. Instead of creating one and destroying it when the command is
1071 * handled, process that right before so we save some round trip in useless
1072 * code path.
1073 */
1074 switch (cmd_ctx->lsm.cmd_type) {
1075 case LTTNG_DISABLE_CHANNEL:
1076 case LTTNG_DISABLE_EVENT:
1077 switch (cmd_ctx->lsm.domain.type) {
1078 case LTTNG_DOMAIN_KERNEL:
1079 if (!cmd_ctx->session->kernel_session) {
1080 ret = LTTNG_ERR_NO_CHANNEL;
1081 goto error;
1082 }
1083 break;
1084 case LTTNG_DOMAIN_JUL:
1085 case LTTNG_DOMAIN_LOG4J:
1086 case LTTNG_DOMAIN_PYTHON:
1087 case LTTNG_DOMAIN_UST:
1088 if (!cmd_ctx->session->ust_session) {
1089 ret = LTTNG_ERR_NO_CHANNEL;
1090 goto error;
1091 }
1092 break;
1093 default:
1094 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1095 goto error;
1096 }
1097 default:
1098 break;
1099 }
1100
1101 if (!need_domain) {
1102 goto skip_domain;
1103 }
1104
1105 /*
1106 * Check domain type for specific "pre-action".
1107 */
1108 switch (cmd_ctx->lsm.domain.type) {
1109 case LTTNG_DOMAIN_KERNEL:
1110 if (!is_root) {
1111 ret = LTTNG_ERR_NEED_ROOT_SESSIOND;
1112 goto error;
1113 }
1114
1115 /* Kernel tracer check */
1116 if (!kernel_tracer_is_initialized()) {
1117 /* Basically, load kernel tracer modules */
1118 ret = init_kernel_tracer();
1119 if (ret != 0) {
1120 goto error;
1121 }
1122 }
1123
1124 /* Consumer is in an ERROR state. Report back to client */
1125 if (need_consumerd && uatomic_read(&the_kernel_consumerd_state) ==
1126 CONSUMER_ERROR) {
1127 ret = LTTNG_ERR_NO_KERNCONSUMERD;
1128 goto error;
1129 }
1130
1131 /* Need a session for kernel command */
1132 if (need_tracing_session) {
1133 if (cmd_ctx->session->kernel_session == NULL) {
1134 ret = create_kernel_session(cmd_ctx->session);
1135 if (ret != LTTNG_OK) {
1136 ret = LTTNG_ERR_KERN_SESS_FAIL;
1137 goto error;
1138 }
1139 }
1140
1141 /* Start the kernel consumer daemon */
1142 pthread_mutex_lock(&the_kconsumer_data.pid_mutex);
1143 if (the_kconsumer_data.pid == 0 &&
1144 cmd_ctx->lsm.cmd_type != LTTNG_REGISTER_CONSUMER) {
1145 pthread_mutex_unlock(&the_kconsumer_data.pid_mutex);
1146 ret = start_consumerd(&the_kconsumer_data);
1147 if (ret < 0) {
1148 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
1149 goto error;
1150 }
1151 uatomic_set(&the_kernel_consumerd_state, CONSUMER_STARTED);
1152 } else {
1153 pthread_mutex_unlock(&the_kconsumer_data.pid_mutex);
1154 }
1155
1156 /*
1157 * The consumer was just spawned so we need to add the socket to
1158 * the consumer output of the session if exist.
1159 */
1160 ret = consumer_create_socket(&the_kconsumer_data,
1161 cmd_ctx->session->kernel_session->consumer);
1162 if (ret < 0) {
1163 goto error;
1164 }
1165 }
1166
1167 break;
1168 case LTTNG_DOMAIN_JUL:
1169 case LTTNG_DOMAIN_LOG4J:
1170 case LTTNG_DOMAIN_PYTHON:
1171 if (!agent_tracing_is_enabled()) {
1172 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
1173 goto error;
1174 }
1175 /* Fallthrough */
1176 case LTTNG_DOMAIN_UST:
1177 {
1178 if (!ust_app_supported()) {
1179 ret = LTTNG_ERR_NO_UST;
1180 goto error;
1181 }
1182
1183 /* Consumer is in an ERROR state. Report back to client */
1184 if (need_consumerd &&
1185 uatomic_read(&the_ust_consumerd_state) ==
1186 CONSUMER_ERROR) {
1187 ret = LTTNG_ERR_NO_USTCONSUMERD;
1188 goto error;
1189 }
1190
1191 if (need_tracing_session) {
1192 /* Create UST session if none exist. */
1193 if (cmd_ctx->session->ust_session == NULL) {
1194 ret = create_ust_session(cmd_ctx->session,
1195 ALIGNED_CONST_PTR(cmd_ctx->lsm.domain));
1196 if (ret != LTTNG_OK) {
1197 goto error;
1198 }
1199 }
1200
1201 /* Start the UST consumer daemons */
1202 /* 64-bit */
1203 pthread_mutex_lock(&the_ustconsumer64_data.pid_mutex);
1204 if (the_config.consumerd64_bin_path.value &&
1205 the_ustconsumer64_data.pid == 0 &&
1206 cmd_ctx->lsm.cmd_type != LTTNG_REGISTER_CONSUMER) {
1207 pthread_mutex_unlock(&the_ustconsumer64_data.pid_mutex);
1208 ret = start_consumerd(&the_ustconsumer64_data);
1209 if (ret < 0) {
1210 ret = LTTNG_ERR_UST_CONSUMER64_FAIL;
1211 uatomic_set(&the_ust_consumerd64_fd, -EINVAL);
1212 goto error;
1213 }
1214
1215 uatomic_set(&the_ust_consumerd64_fd, the_ustconsumer64_data.cmd_sock);
1216 uatomic_set(&the_ust_consumerd_state, CONSUMER_STARTED);
1217 } else {
1218 pthread_mutex_unlock(&the_ustconsumer64_data.pid_mutex);
1219 }
1220
1221 /*
1222 * Setup socket for consumer 64 bit. No need for atomic access
1223 * since it was set above and can ONLY be set in this thread.
1224 */
1225 ret = consumer_create_socket(&the_ustconsumer64_data,
1226 cmd_ctx->session->ust_session->consumer);
1227 if (ret < 0) {
1228 goto error;
1229 }
1230
1231 /* 32-bit */
1232 pthread_mutex_lock(&the_ustconsumer32_data.pid_mutex);
1233 if (the_config.consumerd32_bin_path.value &&
1234 the_ustconsumer32_data.pid == 0 &&
1235 cmd_ctx->lsm.cmd_type != LTTNG_REGISTER_CONSUMER) {
1236 pthread_mutex_unlock(&the_ustconsumer32_data.pid_mutex);
1237 ret = start_consumerd(&the_ustconsumer32_data);
1238 if (ret < 0) {
1239 ret = LTTNG_ERR_UST_CONSUMER32_FAIL;
1240 uatomic_set(&the_ust_consumerd32_fd, -EINVAL);
1241 goto error;
1242 }
1243
1244 uatomic_set(&the_ust_consumerd32_fd, the_ustconsumer32_data.cmd_sock);
1245 uatomic_set(&the_ust_consumerd_state, CONSUMER_STARTED);
1246 } else {
1247 pthread_mutex_unlock(&the_ustconsumer32_data.pid_mutex);
1248 }
1249
1250 /*
1251 * Setup socket for consumer 32 bit. No need for atomic access
1252 * since it was set above and can ONLY be set in this thread.
1253 */
1254 ret = consumer_create_socket(&the_ustconsumer32_data,
1255 cmd_ctx->session->ust_session->consumer);
1256 if (ret < 0) {
1257 goto error;
1258 }
1259 }
1260 break;
1261 }
1262 default:
1263 break;
1264 }
1265 skip_domain:
1266
1267 /* Validate consumer daemon state when start/stop trace command */
1268 if (cmd_ctx->lsm.cmd_type == LTTNG_START_TRACE ||
1269 cmd_ctx->lsm.cmd_type == LTTNG_STOP_TRACE) {
1270 switch (cmd_ctx->lsm.domain.type) {
1271 case LTTNG_DOMAIN_NONE:
1272 break;
1273 case LTTNG_DOMAIN_JUL:
1274 case LTTNG_DOMAIN_LOG4J:
1275 case LTTNG_DOMAIN_PYTHON:
1276 case LTTNG_DOMAIN_UST:
1277 if (uatomic_read(&the_ust_consumerd_state) != CONSUMER_STARTED) {
1278 ret = LTTNG_ERR_NO_USTCONSUMERD;
1279 goto error;
1280 }
1281 break;
1282 case LTTNG_DOMAIN_KERNEL:
1283 if (uatomic_read(&the_kernel_consumerd_state) != CONSUMER_STARTED) {
1284 ret = LTTNG_ERR_NO_KERNCONSUMERD;
1285 goto error;
1286 }
1287 break;
1288 default:
1289 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1290 goto error;
1291 }
1292 }
1293
1294 /*
1295 * Check that the UID matches that of the tracing session.
1296 * The root user can interact with all sessions.
1297 */
1298 if (need_tracing_session) {
1299 if (!session_access_ok(cmd_ctx->session,
1300 LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds)) ||
1301 cmd_ctx->session->destroyed) {
1302 ret = LTTNG_ERR_EPERM;
1303 goto error;
1304 }
1305 }
1306
1307 /*
1308 * Send relayd information to consumer as soon as we have a domain and a
1309 * session defined.
1310 */
1311 if (cmd_ctx->session && need_domain) {
1312 /*
1313 * Setup relayd if not done yet. If the relayd information was already
1314 * sent to the consumer, this call will gracefully return.
1315 */
1316 ret = cmd_setup_relayd(cmd_ctx->session);
1317 if (ret != LTTNG_OK) {
1318 goto error;
1319 }
1320 }
1321
1322 /* Process by command type */
1323 switch (cmd_ctx->lsm.cmd_type) {
1324 case LTTNG_ADD_CONTEXT:
1325 {
1326 /*
1327 * An LTTNG_ADD_CONTEXT command might have a supplementary
1328 * payload if the context being added is an application context.
1329 */
1330 if (cmd_ctx->lsm.u.context.ctx.ctx ==
1331 LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
1332 char *provider_name = NULL, *context_name = NULL;
1333 size_t provider_name_len =
1334 cmd_ctx->lsm.u.context.provider_name_len;
1335 size_t context_name_len =
1336 cmd_ctx->lsm.u.context.context_name_len;
1337
1338 if (provider_name_len == 0 || context_name_len == 0) {
1339 /*
1340 * Application provider and context names MUST
1341 * be provided.
1342 */
1343 ret = -LTTNG_ERR_INVALID;
1344 goto error;
1345 }
1346
1347 provider_name = zmalloc(provider_name_len + 1);
1348 if (!provider_name) {
1349 ret = -LTTNG_ERR_NOMEM;
1350 goto error;
1351 }
1352 cmd_ctx->lsm.u.context.ctx.u.app_ctx.provider_name =
1353 provider_name;
1354
1355 context_name = zmalloc(context_name_len + 1);
1356 if (!context_name) {
1357 ret = -LTTNG_ERR_NOMEM;
1358 goto error_add_context;
1359 }
1360 cmd_ctx->lsm.u.context.ctx.u.app_ctx.ctx_name =
1361 context_name;
1362
1363 ret = lttcomm_recv_unix_sock(*sock, provider_name,
1364 provider_name_len);
1365 if (ret < 0) {
1366 goto error_add_context;
1367 }
1368
1369 ret = lttcomm_recv_unix_sock(*sock, context_name,
1370 context_name_len);
1371 if (ret < 0) {
1372 goto error_add_context;
1373 }
1374 }
1375
1376 /*
1377 * cmd_add_context assumes ownership of the provider and context
1378 * names.
1379 */
1380 ret = cmd_add_context(cmd_ctx->session,
1381 cmd_ctx->lsm.domain.type,
1382 cmd_ctx->lsm.u.context.channel_name,
1383 ALIGNED_CONST_PTR(cmd_ctx->lsm.u.context.ctx),
1384 the_kernel_poll_pipe[1]);
1385
1386 cmd_ctx->lsm.u.context.ctx.u.app_ctx.provider_name = NULL;
1387 cmd_ctx->lsm.u.context.ctx.u.app_ctx.ctx_name = NULL;
1388 error_add_context:
1389 free(cmd_ctx->lsm.u.context.ctx.u.app_ctx.provider_name);
1390 free(cmd_ctx->lsm.u.context.ctx.u.app_ctx.ctx_name);
1391 if (ret < 0) {
1392 goto error;
1393 }
1394 break;
1395 }
1396 case LTTNG_DISABLE_CHANNEL:
1397 {
1398 ret = cmd_disable_channel(cmd_ctx->session, cmd_ctx->lsm.domain.type,
1399 cmd_ctx->lsm.u.disable.channel_name);
1400 break;
1401 }
1402 case LTTNG_DISABLE_EVENT:
1403 {
1404
1405 /*
1406 * FIXME: handle filter; for now we just receive the filter's
1407 * bytecode along with the filter expression which are sent by
1408 * liblttng-ctl and discard them.
1409 *
1410 * This fixes an issue where the client may block while sending
1411 * the filter payload and encounter an error because the session
1412 * daemon closes the socket without ever handling this data.
1413 */
1414 size_t count = cmd_ctx->lsm.u.disable.expression_len +
1415 cmd_ctx->lsm.u.disable.bytecode_len;
1416
1417 if (count) {
1418 char data[LTTNG_FILTER_MAX_LEN];
1419
1420 DBG("Discarding disable event command payload of size %zu", count);
1421 while (count) {
1422 ret = lttcomm_recv_unix_sock(*sock, data,
1423 count > sizeof(data) ? sizeof(data) : count);
1424 if (ret < 0) {
1425 goto error;
1426 }
1427
1428 count -= (size_t) ret;
1429 }
1430 }
1431 ret = cmd_disable_event(cmd_ctx->session, cmd_ctx->lsm.domain.type,
1432 cmd_ctx->lsm.u.disable.channel_name,
1433 ALIGNED_CONST_PTR(cmd_ctx->lsm.u.disable.event));
1434 break;
1435 }
1436 case LTTNG_ENABLE_CHANNEL:
1437 {
1438 cmd_ctx->lsm.u.channel.chan.attr.extended.ptr =
1439 (struct lttng_channel_extended *) &cmd_ctx->lsm.u.channel.extended;
1440 ret = cmd_enable_channel(cmd_ctx->session,
1441 ALIGNED_CONST_PTR(cmd_ctx->lsm.domain),
1442 ALIGNED_CONST_PTR(cmd_ctx->lsm.u.channel.chan),
1443 the_kernel_poll_pipe[1]);
1444 break;
1445 }
1446 case LTTNG_PROCESS_ATTR_TRACKER_ADD_INCLUDE_VALUE:
1447 case LTTNG_PROCESS_ATTR_TRACKER_REMOVE_INCLUDE_VALUE:
1448 {
1449 struct lttng_dynamic_buffer payload;
1450 struct lttng_buffer_view payload_view;
1451 const bool add_value =
1452 cmd_ctx->lsm.cmd_type ==
1453 LTTNG_PROCESS_ATTR_TRACKER_ADD_INCLUDE_VALUE;
1454 const size_t name_len =
1455 cmd_ctx->lsm.u.process_attr_tracker_add_remove_include_value
1456 .name_len;
1457 const enum lttng_domain_type domain_type =
1458 (enum lttng_domain_type)
1459 cmd_ctx->lsm.domain.type;
1460 const enum lttng_process_attr process_attr =
1461 (enum lttng_process_attr) cmd_ctx->lsm.u
1462 .process_attr_tracker_add_remove_include_value
1463 .process_attr;
1464 const enum lttng_process_attr_value_type value_type =
1465 (enum lttng_process_attr_value_type) cmd_ctx
1466 ->lsm.u
1467 .process_attr_tracker_add_remove_include_value
1468 .value_type;
1469 struct process_attr_value *value;
1470 enum lttng_error_code ret_code;
1471 long login_name_max;
1472
1473 login_name_max = sysconf(_SC_LOGIN_NAME_MAX);
1474 if (login_name_max < 0) {
1475 PERROR("Failed to get _SC_LOGIN_NAME_MAX system configuration");
1476 ret = LTTNG_ERR_INVALID;
1477 goto error;
1478 }
1479
1480 /* Receive remaining variable length payload if applicable. */
1481 if (name_len > login_name_max) {
1482 /*
1483 * POSIX mandates user and group names that are at least
1484 * 8 characters long. Note that although shadow-utils
1485 * (useradd, groupaadd, etc.) use 32 chars as their
1486 * limit (from bits/utmp.h, UT_NAMESIZE),
1487 * LOGIN_NAME_MAX is defined to 256.
1488 */
1489 ERR("Rejecting process attribute tracker value %s as the provided exceeds the maximal allowed length: argument length = %zu, maximal length = %ld",
1490 add_value ? "addition" : "removal",
1491 name_len, login_name_max);
1492 ret = LTTNG_ERR_INVALID;
1493 goto error;
1494 }
1495
1496 lttng_dynamic_buffer_init(&payload);
1497 if (name_len != 0) {
1498 /*
1499 * Receive variable payload for user/group name
1500 * arguments.
1501 */
1502 ret = lttng_dynamic_buffer_set_size(&payload, name_len);
1503 if (ret) {
1504 ERR("Failed to allocate buffer to receive payload of %s process attribute tracker value argument",
1505 add_value ? "add" : "remove");
1506 ret = LTTNG_ERR_NOMEM;
1507 goto error_add_remove_tracker_value;
1508 }
1509
1510 ret = lttcomm_recv_unix_sock(
1511 *sock, payload.data, name_len);
1512 if (ret <= 0) {
1513 ERR("Failed to receive payload of %s process attribute tracker value argument",
1514 add_value ? "add" : "remove");
1515 *sock_error = 1;
1516 ret = LTTNG_ERR_INVALID_PROTOCOL;
1517 goto error_add_remove_tracker_value;
1518 }
1519 }
1520
1521 payload_view = lttng_buffer_view_from_dynamic_buffer(
1522 &payload, 0, name_len);
1523 if (name_len > 0 && !lttng_buffer_view_is_valid(&payload_view)) {
1524 ret = LTTNG_ERR_INVALID_PROTOCOL;
1525 goto error_add_remove_tracker_value;
1526 }
1527
1528 /*
1529 * Validate the value type and domains are legal for the process
1530 * attribute tracker that is specified and convert the value to
1531 * add/remove to the internal sessiond representation.
1532 */
1533 ret_code = process_attr_value_from_comm(domain_type,
1534 process_attr, value_type,
1535 &cmd_ctx->lsm.u.process_attr_tracker_add_remove_include_value
1536 .integral_value,
1537 &payload_view, &value);
1538 if (ret_code != LTTNG_OK) {
1539 ret = ret_code;
1540 goto error_add_remove_tracker_value;
1541 }
1542
1543 if (add_value) {
1544 ret = cmd_process_attr_tracker_inclusion_set_add_value(
1545 cmd_ctx->session, domain_type,
1546 process_attr, value);
1547 } else {
1548 ret = cmd_process_attr_tracker_inclusion_set_remove_value(
1549 cmd_ctx->session, domain_type,
1550 process_attr, value);
1551 }
1552 process_attr_value_destroy(value);
1553 error_add_remove_tracker_value:
1554 lttng_dynamic_buffer_reset(&payload);
1555 break;
1556 }
1557 case LTTNG_PROCESS_ATTR_TRACKER_GET_POLICY:
1558 {
1559 enum lttng_tracking_policy tracking_policy;
1560 const enum lttng_domain_type domain_type =
1561 (enum lttng_domain_type)
1562 cmd_ctx->lsm.domain.type;
1563 const enum lttng_process_attr process_attr =
1564 (enum lttng_process_attr) cmd_ctx->lsm.u
1565 .process_attr_tracker_get_tracking_policy
1566 .process_attr;
1567
1568 ret = cmd_process_attr_tracker_get_tracking_policy(
1569 cmd_ctx->session, domain_type, process_attr,
1570 &tracking_policy);
1571 if (ret != LTTNG_OK) {
1572 goto error;
1573 }
1574
1575 ret = setup_lttng_msg_no_cmd_header(cmd_ctx,
1576 &(uint32_t){tracking_policy}, sizeof(uint32_t));
1577 if (ret < 0) {
1578 ret = LTTNG_ERR_NOMEM;
1579 goto error;
1580 }
1581 ret = LTTNG_OK;
1582 break;
1583 }
1584 case LTTNG_PROCESS_ATTR_TRACKER_SET_POLICY:
1585 {
1586 const enum lttng_tracking_policy tracking_policy =
1587 (enum lttng_tracking_policy) cmd_ctx->lsm.u
1588 .process_attr_tracker_set_tracking_policy
1589 .tracking_policy;
1590 const enum lttng_domain_type domain_type =
1591 (enum lttng_domain_type)
1592 cmd_ctx->lsm.domain.type;
1593 const enum lttng_process_attr process_attr =
1594 (enum lttng_process_attr) cmd_ctx->lsm.u
1595 .process_attr_tracker_set_tracking_policy
1596 .process_attr;
1597
1598 ret = cmd_process_attr_tracker_set_tracking_policy(
1599 cmd_ctx->session, domain_type, process_attr,
1600 tracking_policy);
1601 if (ret != LTTNG_OK) {
1602 goto error;
1603 }
1604 break;
1605 }
1606 case LTTNG_PROCESS_ATTR_TRACKER_GET_INCLUSION_SET:
1607 {
1608 struct lttng_process_attr_values *values;
1609 struct lttng_dynamic_buffer reply;
1610 const enum lttng_domain_type domain_type =
1611 (enum lttng_domain_type)
1612 cmd_ctx->lsm.domain.type;
1613 const enum lttng_process_attr process_attr =
1614 (enum lttng_process_attr) cmd_ctx->lsm.u
1615 .process_attr_tracker_get_inclusion_set
1616 .process_attr;
1617
1618 ret = cmd_process_attr_tracker_get_inclusion_set(
1619 cmd_ctx->session, domain_type, process_attr,
1620 &values);
1621 if (ret != LTTNG_OK) {
1622 goto error;
1623 }
1624
1625 lttng_dynamic_buffer_init(&reply);
1626 ret = lttng_process_attr_values_serialize(values, &reply);
1627 if (ret < 0) {
1628 goto error_tracker_get_inclusion_set;
1629 }
1630
1631 ret = setup_lttng_msg_no_cmd_header(
1632 cmd_ctx, reply.data, reply.size);
1633 if (ret < 0) {
1634 ret = LTTNG_ERR_NOMEM;
1635 goto error_tracker_get_inclusion_set;
1636 }
1637 ret = LTTNG_OK;
1638
1639 error_tracker_get_inclusion_set:
1640 lttng_process_attr_values_destroy(values);
1641 lttng_dynamic_buffer_reset(&reply);
1642 break;
1643 }
1644 case LTTNG_ENABLE_EVENT:
1645 {
1646 struct lttng_event *ev = NULL;
1647 struct lttng_event_exclusion *exclusion = NULL;
1648 struct lttng_bytecode *bytecode = NULL;
1649 char *filter_expression = NULL;
1650
1651 /* Handle exclusion events and receive it from the client. */
1652 if (cmd_ctx->lsm.u.enable.exclusion_count > 0) {
1653 size_t count = cmd_ctx->lsm.u.enable.exclusion_count;
1654
1655 exclusion = zmalloc(sizeof(struct lttng_event_exclusion) +
1656 (count * LTTNG_SYMBOL_NAME_LEN));
1657 if (!exclusion) {
1658 ret = LTTNG_ERR_EXCLUSION_NOMEM;
1659 goto error;
1660 }
1661
1662 DBG("Receiving var len exclusion event list from client ...");
1663 exclusion->count = count;
1664 ret = lttcomm_recv_unix_sock(*sock, exclusion->names,
1665 count * LTTNG_SYMBOL_NAME_LEN);
1666 if (ret <= 0) {
1667 DBG("Nothing recv() from client var len data... continuing");
1668 *sock_error = 1;
1669 free(exclusion);
1670 ret = LTTNG_ERR_EXCLUSION_INVAL;
1671 goto error;
1672 }
1673 }
1674
1675 /* Get filter expression from client. */
1676 if (cmd_ctx->lsm.u.enable.expression_len > 0) {
1677 size_t expression_len =
1678 cmd_ctx->lsm.u.enable.expression_len;
1679
1680 if (expression_len > LTTNG_FILTER_MAX_LEN) {
1681 ret = LTTNG_ERR_FILTER_INVAL;
1682 free(exclusion);
1683 goto error;
1684 }
1685
1686 filter_expression = zmalloc(expression_len);
1687 if (!filter_expression) {
1688 free(exclusion);
1689 ret = LTTNG_ERR_FILTER_NOMEM;
1690 goto error;
1691 }
1692
1693 /* Receive var. len. data */
1694 DBG("Receiving var len filter's expression from client ...");
1695 ret = lttcomm_recv_unix_sock(*sock, filter_expression,
1696 expression_len);
1697 if (ret <= 0) {
1698 DBG("Nothing recv() from client var len data... continuing");
1699 *sock_error = 1;
1700 free(filter_expression);
1701 free(exclusion);
1702 ret = LTTNG_ERR_FILTER_INVAL;
1703 goto error;
1704 }
1705 }
1706
1707 /* Handle filter and get bytecode from client. */
1708 if (cmd_ctx->lsm.u.enable.bytecode_len > 0) {
1709 size_t bytecode_len = cmd_ctx->lsm.u.enable.bytecode_len;
1710
1711 if (bytecode_len > LTTNG_FILTER_MAX_LEN) {
1712 ret = LTTNG_ERR_FILTER_INVAL;
1713 free(filter_expression);
1714 free(exclusion);
1715 goto error;
1716 }
1717
1718 bytecode = zmalloc(bytecode_len);
1719 if (!bytecode) {
1720 free(filter_expression);
1721 free(exclusion);
1722 ret = LTTNG_ERR_FILTER_NOMEM;
1723 goto error;
1724 }
1725
1726 /* Receive var. len. data */
1727 DBG("Receiving var len filter's bytecode from client ...");
1728 ret = lttcomm_recv_unix_sock(*sock, bytecode, bytecode_len);
1729 if (ret <= 0) {
1730 DBG("Nothing recv() from client var len data... continuing");
1731 *sock_error = 1;
1732 free(filter_expression);
1733 free(bytecode);
1734 free(exclusion);
1735 ret = LTTNG_ERR_FILTER_INVAL;
1736 goto error;
1737 }
1738
1739 if ((bytecode->len + sizeof(*bytecode)) != bytecode_len) {
1740 free(filter_expression);
1741 free(bytecode);
1742 free(exclusion);
1743 ret = LTTNG_ERR_FILTER_INVAL;
1744 goto error;
1745 }
1746 }
1747
1748 ev = lttng_event_copy(ALIGNED_CONST_PTR(cmd_ctx->lsm.u.enable.event));
1749 if (!ev) {
1750 DBG("Failed to copy event: %s",
1751 cmd_ctx->lsm.u.enable.event.name);
1752 free(filter_expression);
1753 free(bytecode);
1754 free(exclusion);
1755 ret = LTTNG_ERR_NOMEM;
1756 goto error;
1757 }
1758
1759
1760 if (cmd_ctx->lsm.u.enable.userspace_probe_location_len > 0) {
1761 /* Expect a userspace probe description. */
1762 ret = receive_userspace_probe(cmd_ctx, *sock, sock_error, ev);
1763 if (ret) {
1764 free(filter_expression);
1765 free(bytecode);
1766 free(exclusion);
1767 lttng_event_destroy(ev);
1768 goto error;
1769 }
1770 }
1771
1772 ret = cmd_enable_event(cmd_ctx->session,
1773 ALIGNED_CONST_PTR(cmd_ctx->lsm.domain),
1774 cmd_ctx->lsm.u.enable.channel_name,
1775 ev,
1776 filter_expression, bytecode, exclusion,
1777 the_kernel_poll_pipe[1]);
1778 lttng_event_destroy(ev);
1779 break;
1780 }
1781 case LTTNG_LIST_TRACEPOINTS:
1782 {
1783 struct lttng_event *events;
1784 ssize_t nb_events;
1785
1786 session_lock_list();
1787 nb_events = cmd_list_tracepoints(cmd_ctx->lsm.domain.type, &events);
1788 session_unlock_list();
1789 if (nb_events < 0) {
1790 /* Return value is a negative lttng_error_code. */
1791 ret = -nb_events;
1792 goto error;
1793 }
1794
1795 /*
1796 * Setup lttng message with payload size set to the event list size in
1797 * bytes and then copy list into the llm payload.
1798 */
1799 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, events,
1800 sizeof(struct lttng_event) * nb_events);
1801 free(events);
1802
1803 if (ret < 0) {
1804 goto setup_error;
1805 }
1806
1807 ret = LTTNG_OK;
1808 break;
1809 }
1810 case LTTNG_LIST_TRACEPOINT_FIELDS:
1811 {
1812 struct lttng_event_field *fields;
1813 ssize_t nb_fields;
1814
1815 session_lock_list();
1816 nb_fields = cmd_list_tracepoint_fields(cmd_ctx->lsm.domain.type,
1817 &fields);
1818 session_unlock_list();
1819 if (nb_fields < 0) {
1820 /* Return value is a negative lttng_error_code. */
1821 ret = -nb_fields;
1822 goto error;
1823 }
1824
1825 /*
1826 * Setup lttng message with payload size set to the event list size in
1827 * bytes and then copy list into the llm payload.
1828 */
1829 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, fields,
1830 sizeof(struct lttng_event_field) * nb_fields);
1831 free(fields);
1832
1833 if (ret < 0) {
1834 goto setup_error;
1835 }
1836
1837 ret = LTTNG_OK;
1838 break;
1839 }
1840 case LTTNG_LIST_SYSCALLS:
1841 {
1842 struct lttng_event *events;
1843 ssize_t nb_events;
1844
1845 nb_events = cmd_list_syscalls(&events);
1846 if (nb_events < 0) {
1847 /* Return value is a negative lttng_error_code. */
1848 ret = -nb_events;
1849 goto error;
1850 }
1851
1852 /*
1853 * Setup lttng message with payload size set to the event list size in
1854 * bytes and then copy list into the llm payload.
1855 */
1856 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, events,
1857 sizeof(struct lttng_event) * nb_events);
1858 free(events);
1859
1860 if (ret < 0) {
1861 goto setup_error;
1862 }
1863
1864 ret = LTTNG_OK;
1865 break;
1866 }
1867 case LTTNG_SET_CONSUMER_URI:
1868 {
1869 size_t nb_uri, len;
1870 struct lttng_uri *uris;
1871
1872 nb_uri = cmd_ctx->lsm.u.uri.size;
1873 len = nb_uri * sizeof(struct lttng_uri);
1874
1875 if (nb_uri == 0) {
1876 ret = LTTNG_ERR_INVALID;
1877 goto error;
1878 }
1879
1880 uris = zmalloc(len);
1881 if (uris == NULL) {
1882 ret = LTTNG_ERR_FATAL;
1883 goto error;
1884 }
1885
1886 /* Receive variable len data */
1887 DBG("Receiving %zu URI(s) from client ...", nb_uri);
1888 ret = lttcomm_recv_unix_sock(*sock, uris, len);
1889 if (ret <= 0) {
1890 DBG("No URIs received from client... continuing");
1891 *sock_error = 1;
1892 ret = LTTNG_ERR_SESSION_FAIL;
1893 free(uris);
1894 goto error;
1895 }
1896
1897 ret = cmd_set_consumer_uri(cmd_ctx->session, nb_uri, uris);
1898 free(uris);
1899 if (ret != LTTNG_OK) {
1900 goto error;
1901 }
1902
1903
1904 break;
1905 }
1906 case LTTNG_START_TRACE:
1907 {
1908 /*
1909 * On the first start, if we have a kernel session and we have
1910 * enabled time or size-based rotations, we have to make sure
1911 * the kernel tracer supports it.
1912 */
1913 if (!cmd_ctx->session->has_been_started && \
1914 cmd_ctx->session->kernel_session && \
1915 (cmd_ctx->session->rotate_timer_period || \
1916 cmd_ctx->session->rotate_size) && \
1917 !check_rotate_compatible()) {
1918 DBG("Kernel tracer version is not compatible with the rotation feature");
1919 ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
1920 goto error;
1921 }
1922 ret = cmd_start_trace(cmd_ctx->session);
1923 break;
1924 }
1925 case LTTNG_STOP_TRACE:
1926 {
1927 ret = cmd_stop_trace(cmd_ctx->session);
1928 break;
1929 }
1930 case LTTNG_DESTROY_SESSION:
1931 {
1932 ret = cmd_destroy_session(cmd_ctx->session,
1933 the_notification_thread_handle, sock);
1934 break;
1935 }
1936 case LTTNG_LIST_DOMAINS:
1937 {
1938 ssize_t nb_dom;
1939 struct lttng_domain *domains = NULL;
1940
1941 nb_dom = cmd_list_domains(cmd_ctx->session, &domains);
1942 if (nb_dom < 0) {
1943 /* Return value is a negative lttng_error_code. */
1944 ret = -nb_dom;
1945 goto error;
1946 }
1947
1948 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, domains,
1949 nb_dom * sizeof(struct lttng_domain));
1950 free(domains);
1951
1952 if (ret < 0) {
1953 goto setup_error;
1954 }
1955
1956 ret = LTTNG_OK;
1957 break;
1958 }
1959 case LTTNG_LIST_CHANNELS:
1960 {
1961 ssize_t payload_size;
1962 struct lttng_channel *channels = NULL;
1963
1964 payload_size = cmd_list_channels(cmd_ctx->lsm.domain.type,
1965 cmd_ctx->session, &channels);
1966 if (payload_size < 0) {
1967 /* Return value is a negative lttng_error_code. */
1968 ret = -payload_size;
1969 goto error;
1970 }
1971
1972 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, channels,
1973 payload_size);
1974 free(channels);
1975
1976 if (ret < 0) {
1977 goto setup_error;
1978 }
1979
1980 ret = LTTNG_OK;
1981 break;
1982 }
1983 case LTTNG_LIST_EVENTS:
1984 {
1985 ssize_t list_ret;
1986 struct lttcomm_event_command_header cmd_header = {};
1987 size_t original_payload_size;
1988 size_t payload_size;
1989
1990 ret = setup_empty_lttng_msg(cmd_ctx);
1991 if (ret) {
1992 ret = LTTNG_ERR_NOMEM;
1993 goto setup_error;
1994 }
1995
1996 original_payload_size = cmd_ctx->reply_payload.buffer.size;
1997
1998 /* Extended infos are included at the end of the payload. */
1999 list_ret = cmd_list_events(cmd_ctx->lsm.domain.type,
2000 cmd_ctx->session,
2001 cmd_ctx->lsm.u.list.channel_name,
2002 &cmd_ctx->reply_payload);
2003 if (list_ret < 0) {
2004 /* Return value is a negative lttng_error_code. */
2005 ret = -list_ret;
2006 goto error;
2007 }
2008
2009 payload_size = cmd_ctx->reply_payload.buffer.size -
2010 sizeof(cmd_header) - original_payload_size;
2011 update_lttng_msg(cmd_ctx, sizeof(cmd_header), payload_size);
2012
2013 ret = LTTNG_OK;
2014 break;
2015 }
2016 case LTTNG_LIST_SESSIONS:
2017 {
2018 unsigned int nr_sessions;
2019 void *sessions_payload;
2020 size_t payload_len;
2021
2022 session_lock_list();
2023 nr_sessions = lttng_sessions_count(
2024 LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
2025 LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds));
2026
2027 payload_len = (sizeof(struct lttng_session) * nr_sessions) +
2028 (sizeof(struct lttng_session_extended) * nr_sessions);
2029 sessions_payload = zmalloc(payload_len);
2030
2031 if (!sessions_payload) {
2032 session_unlock_list();
2033 ret = -ENOMEM;
2034 goto setup_error;
2035 }
2036
2037 cmd_list_lttng_sessions(sessions_payload, nr_sessions,
2038 LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
2039 LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds));
2040 session_unlock_list();
2041
2042 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, sessions_payload,
2043 payload_len);
2044 free(sessions_payload);
2045
2046 if (ret < 0) {
2047 goto setup_error;
2048 }
2049
2050 ret = LTTNG_OK;
2051 break;
2052 }
2053 case LTTNG_REGISTER_CONSUMER:
2054 {
2055 struct consumer_data *cdata;
2056
2057 switch (cmd_ctx->lsm.domain.type) {
2058 case LTTNG_DOMAIN_KERNEL:
2059 cdata = &the_kconsumer_data;
2060 break;
2061 default:
2062 ret = LTTNG_ERR_UND;
2063 goto error;
2064 }
2065
2066 ret = cmd_register_consumer(cmd_ctx->session, cmd_ctx->lsm.domain.type,
2067 cmd_ctx->lsm.u.reg.path, cdata);
2068 break;
2069 }
2070 case LTTNG_DATA_PENDING:
2071 {
2072 int pending_ret;
2073 uint8_t pending_ret_byte;
2074
2075 pending_ret = cmd_data_pending(cmd_ctx->session);
2076
2077 /*
2078 * FIXME
2079 *
2080 * This function may returns 0 or 1 to indicate whether or not
2081 * there is data pending. In case of error, it should return an
2082 * LTTNG_ERR code. However, some code paths may still return
2083 * a nondescript error code, which we handle by returning an
2084 * "unknown" error.
2085 */
2086 if (pending_ret == 0 || pending_ret == 1) {
2087 /*
2088 * ret will be set to LTTNG_OK at the end of
2089 * this function.
2090 */
2091 } else if (pending_ret < 0) {
2092 ret = LTTNG_ERR_UNK;
2093 goto setup_error;
2094 } else {
2095 ret = pending_ret;
2096 goto setup_error;
2097 }
2098
2099 pending_ret_byte = (uint8_t) pending_ret;
2100
2101 /* 1 byte to return whether or not data is pending */
2102 ret = setup_lttng_msg_no_cmd_header(cmd_ctx,
2103 &pending_ret_byte, 1);
2104
2105 if (ret < 0) {
2106 goto setup_error;
2107 }
2108
2109 ret = LTTNG_OK;
2110 break;
2111 }
2112 case LTTNG_SNAPSHOT_ADD_OUTPUT:
2113 {
2114 uint32_t snapshot_id;
2115 struct lttcomm_lttng_output_id reply;
2116
2117 ret = cmd_snapshot_add_output(cmd_ctx->session,
2118 ALIGNED_CONST_PTR(cmd_ctx->lsm.u.snapshot_output.output),
2119 &snapshot_id);
2120 if (ret != LTTNG_OK) {
2121 goto error;
2122 }
2123 reply.id = snapshot_id;
2124
2125 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &reply,
2126 sizeof(reply));
2127 if (ret < 0) {
2128 goto setup_error;
2129 }
2130
2131 /* Copy output list into message payload */
2132 ret = LTTNG_OK;
2133 break;
2134 }
2135 case LTTNG_SNAPSHOT_DEL_OUTPUT:
2136 {
2137 ret = cmd_snapshot_del_output(cmd_ctx->session,
2138 ALIGNED_CONST_PTR(cmd_ctx->lsm.u.snapshot_output.output));
2139 break;
2140 }
2141 case LTTNG_SNAPSHOT_LIST_OUTPUT:
2142 {
2143 ssize_t nb_output;
2144 struct lttng_snapshot_output *outputs = NULL;
2145
2146 nb_output = cmd_snapshot_list_outputs(cmd_ctx->session, &outputs);
2147 if (nb_output < 0) {
2148 ret = -nb_output;
2149 goto error;
2150 }
2151
2152 LTTNG_ASSERT((nb_output > 0 && outputs) || nb_output == 0);
2153 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, outputs,
2154 nb_output * sizeof(struct lttng_snapshot_output));
2155 free(outputs);
2156
2157 if (ret < 0) {
2158 goto setup_error;
2159 }
2160
2161 ret = LTTNG_OK;
2162 break;
2163 }
2164 case LTTNG_SNAPSHOT_RECORD:
2165 {
2166 ret = cmd_snapshot_record(cmd_ctx->session,
2167 ALIGNED_CONST_PTR(cmd_ctx->lsm.u.snapshot_record.output),
2168 cmd_ctx->lsm.u.snapshot_record.wait);
2169 break;
2170 }
2171 case LTTNG_CREATE_SESSION_EXT:
2172 {
2173 struct lttng_dynamic_buffer payload;
2174 struct lttng_session_descriptor *return_descriptor = NULL;
2175
2176 lttng_dynamic_buffer_init(&payload);
2177 ret = cmd_create_session(cmd_ctx, *sock, &return_descriptor);
2178 if (ret != LTTNG_OK) {
2179 goto error;
2180 }
2181
2182 ret = lttng_session_descriptor_serialize(return_descriptor,
2183 &payload);
2184 if (ret) {
2185 ERR("Failed to serialize session descriptor in reply to \"create session\" command");
2186 lttng_session_descriptor_destroy(return_descriptor);
2187 ret = LTTNG_ERR_NOMEM;
2188 goto error;
2189 }
2190 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, payload.data,
2191 payload.size);
2192 if (ret) {
2193 lttng_session_descriptor_destroy(return_descriptor);
2194 ret = LTTNG_ERR_NOMEM;
2195 goto error;
2196 }
2197 lttng_dynamic_buffer_reset(&payload);
2198 lttng_session_descriptor_destroy(return_descriptor);
2199 ret = LTTNG_OK;
2200 break;
2201 }
2202 case LTTNG_SAVE_SESSION:
2203 {
2204 ret = cmd_save_sessions(&cmd_ctx->lsm.u.save_session.attr,
2205 &cmd_ctx->creds);
2206 break;
2207 }
2208 case LTTNG_SET_SESSION_SHM_PATH:
2209 {
2210 ret = cmd_set_session_shm_path(cmd_ctx->session,
2211 cmd_ctx->lsm.u.set_shm_path.shm_path);
2212 break;
2213 }
2214 case LTTNG_REGENERATE_METADATA:
2215 {
2216 ret = cmd_regenerate_metadata(cmd_ctx->session);
2217 break;
2218 }
2219 case LTTNG_REGENERATE_STATEDUMP:
2220 {
2221 ret = cmd_regenerate_statedump(cmd_ctx->session);
2222 break;
2223 }
2224 case LTTNG_REGISTER_TRIGGER:
2225 {
2226 struct lttng_trigger *payload_trigger;
2227 struct lttng_trigger *return_trigger;
2228 size_t original_reply_payload_size;
2229 size_t reply_payload_size;
2230 const struct lttng_credentials cmd_creds = {
2231 .uid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.uid),
2232 .gid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.gid),
2233 };
2234
2235 ret = setup_empty_lttng_msg(cmd_ctx);
2236 if (ret) {
2237 ret = LTTNG_ERR_NOMEM;
2238 goto setup_error;
2239 }
2240
2241 ret = receive_lttng_trigger(
2242 cmd_ctx, *sock, sock_error, &payload_trigger);
2243 if (ret != LTTNG_OK) {
2244 goto error;
2245 }
2246
2247 original_reply_payload_size = cmd_ctx->reply_payload.buffer.size;
2248
2249 ret = cmd_register_trigger(&cmd_creds, payload_trigger,
2250 cmd_ctx->lsm.u.trigger.is_trigger_anonymous,
2251 the_notification_thread_handle,
2252 &return_trigger);
2253 if (ret != LTTNG_OK) {
2254 lttng_trigger_put(payload_trigger);
2255 goto error;
2256 }
2257
2258 ret = lttng_trigger_serialize(return_trigger, &cmd_ctx->reply_payload);
2259 lttng_trigger_put(payload_trigger);
2260 lttng_trigger_put(return_trigger);
2261 if (ret) {
2262 ERR("Failed to serialize trigger in reply to \"register trigger\" command");
2263 ret = LTTNG_ERR_NOMEM;
2264 goto error;
2265 }
2266
2267 reply_payload_size = cmd_ctx->reply_payload.buffer.size -
2268 original_reply_payload_size;
2269
2270 update_lttng_msg(cmd_ctx, 0, reply_payload_size);
2271
2272 ret = LTTNG_OK;
2273 break;
2274 }
2275 case LTTNG_UNREGISTER_TRIGGER:
2276 {
2277 struct lttng_trigger *payload_trigger;
2278 const struct lttng_credentials cmd_creds = {
2279 .uid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.uid),
2280 .gid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.gid),
2281 };
2282
2283 ret = receive_lttng_trigger(
2284 cmd_ctx, *sock, sock_error, &payload_trigger);
2285 if (ret != LTTNG_OK) {
2286 goto error;
2287 }
2288
2289 ret = cmd_unregister_trigger(&cmd_creds, payload_trigger,
2290 the_notification_thread_handle);
2291 lttng_trigger_put(payload_trigger);
2292 break;
2293 }
2294 case LTTNG_ROTATE_SESSION:
2295 {
2296 struct lttng_rotate_session_return rotate_return;
2297
2298 DBG("Client rotate session \"%s\"", cmd_ctx->session->name);
2299
2300 memset(&rotate_return, 0, sizeof(rotate_return));
2301 if (cmd_ctx->session->kernel_session && !check_rotate_compatible()) {
2302 DBG("Kernel tracer version is not compatible with the rotation feature");
2303 ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
2304 goto error;
2305 }
2306
2307 ret = cmd_rotate_session(cmd_ctx->session, &rotate_return,
2308 false,
2309 LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED);
2310 if (ret < 0) {
2311 ret = -ret;
2312 goto error;
2313 }
2314
2315 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &rotate_return,
2316 sizeof(rotate_return));
2317 if (ret < 0) {
2318 ret = -ret;
2319 goto error;
2320 }
2321
2322 ret = LTTNG_OK;
2323 break;
2324 }
2325 case LTTNG_ROTATION_GET_INFO:
2326 {
2327 struct lttng_rotation_get_info_return get_info_return;
2328
2329 memset(&get_info_return, 0, sizeof(get_info_return));
2330 ret = cmd_rotate_get_info(cmd_ctx->session, &get_info_return,
2331 cmd_ctx->lsm.u.get_rotation_info.rotation_id);
2332 if (ret < 0) {
2333 ret = -ret;
2334 goto error;
2335 }
2336
2337 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &get_info_return,
2338 sizeof(get_info_return));
2339 if (ret < 0) {
2340 ret = -ret;
2341 goto error;
2342 }
2343
2344 ret = LTTNG_OK;
2345 break;
2346 }
2347 case LTTNG_ROTATION_SET_SCHEDULE:
2348 {
2349 bool set_schedule;
2350 enum lttng_rotation_schedule_type schedule_type;
2351 uint64_t value;
2352
2353 if (cmd_ctx->session->kernel_session && !check_rotate_compatible()) {
2354 DBG("Kernel tracer version does not support session rotations");
2355 ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
2356 goto error;
2357 }
2358
2359 set_schedule = cmd_ctx->lsm.u.rotation_set_schedule.set == 1;
2360 schedule_type = (enum lttng_rotation_schedule_type) cmd_ctx->lsm.u.rotation_set_schedule.type;
2361 value = cmd_ctx->lsm.u.rotation_set_schedule.value;
2362
2363 ret = cmd_rotation_set_schedule(cmd_ctx->session, set_schedule,
2364 schedule_type, value,
2365 the_notification_thread_handle);
2366 if (ret != LTTNG_OK) {
2367 goto error;
2368 }
2369
2370 break;
2371 }
2372 case LTTNG_SESSION_LIST_ROTATION_SCHEDULES:
2373 {
2374 struct lttng_session_list_schedules_return schedules = {
2375 .periodic.set = !!cmd_ctx->session->rotate_timer_period,
2376 .periodic.value = cmd_ctx->session->rotate_timer_period,
2377 .size.set = !!cmd_ctx->session->rotate_size,
2378 .size.value = cmd_ctx->session->rotate_size,
2379 };
2380
2381 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &schedules,
2382 sizeof(schedules));
2383 if (ret < 0) {
2384 ret = -ret;
2385 goto error;
2386 }
2387
2388 ret = LTTNG_OK;
2389 break;
2390 }
2391 case LTTNG_CLEAR_SESSION:
2392 {
2393 ret = cmd_clear_session(cmd_ctx->session, sock);
2394 break;
2395 }
2396 case LTTNG_LIST_TRIGGERS:
2397 {
2398 struct lttng_triggers *return_triggers = NULL;
2399 size_t original_payload_size;
2400 size_t payload_size;
2401
2402 ret = setup_empty_lttng_msg(cmd_ctx);
2403 if (ret) {
2404 ret = LTTNG_ERR_NOMEM;
2405 goto setup_error;
2406 }
2407
2408 original_payload_size = cmd_ctx->reply_payload.buffer.size;
2409
2410 ret = cmd_list_triggers(cmd_ctx, the_notification_thread_handle,
2411 &return_triggers);
2412 if (ret != LTTNG_OK) {
2413 goto error;
2414 }
2415
2416 LTTNG_ASSERT(return_triggers);
2417 ret = lttng_triggers_serialize(
2418 return_triggers, &cmd_ctx->reply_payload);
2419 lttng_triggers_destroy(return_triggers);
2420 if (ret) {
2421 ERR("Failed to serialize triggers in reply to `list triggers` command");
2422 ret = LTTNG_ERR_NOMEM;
2423 goto error;
2424 }
2425
2426 payload_size = cmd_ctx->reply_payload.buffer.size -
2427 original_payload_size;
2428
2429 update_lttng_msg(cmd_ctx, 0, payload_size);
2430
2431 ret = LTTNG_OK;
2432 break;
2433 }
2434 case LTTNG_EXECUTE_ERROR_QUERY:
2435 {
2436 struct lttng_error_query *query;
2437 const struct lttng_credentials cmd_creds = {
2438 .uid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.uid),
2439 .gid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.gid),
2440 };
2441 struct lttng_error_query_results *results = NULL;
2442 size_t original_payload_size;
2443 size_t payload_size;
2444
2445 ret = setup_empty_lttng_msg(cmd_ctx);
2446 if (ret) {
2447 ret = LTTNG_ERR_NOMEM;
2448 goto setup_error;
2449 }
2450
2451 original_payload_size = cmd_ctx->reply_payload.buffer.size;
2452
2453 ret = receive_lttng_error_query(
2454 cmd_ctx, *sock, sock_error, &query);
2455 if (ret != LTTNG_OK) {
2456 goto error;
2457 }
2458
2459 ret = cmd_execute_error_query(&cmd_creds, query, &results,
2460 the_notification_thread_handle);
2461 lttng_error_query_destroy(query);
2462 if (ret != LTTNG_OK) {
2463 goto error;
2464 }
2465
2466 LTTNG_ASSERT(results);
2467 ret = lttng_error_query_results_serialize(
2468 results, &cmd_ctx->reply_payload);
2469 lttng_error_query_results_destroy(results);
2470 if (ret) {
2471 ERR("Failed to serialize error query result set in reply to `execute error query` command");
2472 ret = LTTNG_ERR_NOMEM;
2473 goto error;
2474 }
2475
2476 payload_size = cmd_ctx->reply_payload.buffer.size -
2477 original_payload_size;
2478
2479 update_lttng_msg(cmd_ctx, 0, payload_size);
2480
2481 ret = LTTNG_OK;
2482
2483 break;
2484 }
2485 default:
2486 ret = LTTNG_ERR_UND;
2487 break;
2488 }
2489
2490 error:
2491 if (cmd_ctx->reply_payload.buffer.size == 0) {
2492 DBG("Missing llm header, creating one.");
2493 if (setup_lttng_msg_no_cmd_header(cmd_ctx, NULL, 0) < 0) {
2494 goto setup_error;
2495 }
2496 }
2497 /* Set return code */
2498 ((struct lttcomm_lttng_msg *) (cmd_ctx->reply_payload.buffer.data))->ret_code = ret;
2499 setup_error:
2500 if (cmd_ctx->session) {
2501 session_unlock(cmd_ctx->session);
2502 session_put(cmd_ctx->session);
2503 cmd_ctx->session = NULL;
2504 }
2505 if (need_tracing_session) {
2506 session_unlock_list();
2507 }
2508 init_setup_error:
2509 LTTNG_ASSERT(!rcu_read_ongoing());
2510 return ret;
2511 }
2512
2513 static int create_client_sock(void)
2514 {
2515 int ret, client_sock;
2516 const mode_t old_umask = umask(0);
2517
2518 /* Create client tool unix socket */
2519 client_sock = lttcomm_create_unix_sock(
2520 the_config.client_unix_sock_path.value);
2521 if (client_sock < 0) {
2522 ERR("Create unix sock failed: %s",
2523 the_config.client_unix_sock_path.value);
2524 ret = -1;
2525 goto end;
2526 }
2527
2528 /* Set the cloexec flag */
2529 ret = utils_set_fd_cloexec(client_sock);
2530 if (ret < 0) {
2531 ERR("Unable to set CLOEXEC flag to the client Unix socket (fd: %d). "
2532 "Continuing but note that the consumer daemon will have a "
2533 "reference to this socket on exec()", client_sock);
2534 }
2535
2536 /* File permission MUST be 660 */
2537 ret = chmod(the_config.client_unix_sock_path.value,
2538 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
2539 if (ret < 0) {
2540 ERR("Set file permissions failed: %s",
2541 the_config.client_unix_sock_path.value);
2542 PERROR("chmod");
2543 (void) lttcomm_close_unix_sock(client_sock);
2544 ret = -1;
2545 goto end;
2546 }
2547 DBG("Created client socket (fd = %i)", client_sock);
2548 ret = client_sock;
2549 end:
2550 umask(old_umask);
2551 return ret;
2552 }
2553
2554 static void cleanup_client_thread(void *data)
2555 {
2556 struct lttng_pipe *quit_pipe = data;
2557
2558 lttng_pipe_destroy(quit_pipe);
2559 }
2560
2561 static void thread_init_cleanup(void *data)
2562 {
2563 set_thread_status(false);
2564 }
2565
2566 /*
2567 * This thread manage all clients request using the unix client socket for
2568 * communication.
2569 */
2570 static void *thread_manage_clients(void *data)
2571 {
2572 int sock = -1, ret, i, pollfd, err = -1;
2573 int sock_error;
2574 uint32_t revents, nb_fd;
2575 struct lttng_poll_event events;
2576 const int client_sock = thread_state.client_sock;
2577 struct lttng_pipe *quit_pipe = data;
2578 const int thread_quit_pipe_fd = lttng_pipe_get_readfd(quit_pipe);
2579 struct command_ctx cmd_ctx = {};
2580
2581 DBG("[thread] Manage client started");
2582
2583 lttng_payload_init(&cmd_ctx.reply_payload);
2584
2585 is_root = (getuid() == 0);
2586
2587 pthread_cleanup_push(thread_init_cleanup, NULL);
2588
2589 rcu_register_thread();
2590
2591 health_register(the_health_sessiond, HEALTH_SESSIOND_TYPE_CMD);
2592
2593 health_code_update();
2594
2595 ret = lttcomm_listen_unix_sock(client_sock);
2596 if (ret < 0) {
2597 goto error_listen;
2598 }
2599
2600 /*
2601 * Pass 2 as size here for the thread quit pipe and client_sock. Nothing
2602 * more will be added to this poll set.
2603 */
2604 ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
2605 if (ret < 0) {
2606 goto error_create_poll;
2607 }
2608
2609 /* Add the application registration socket */
2610 ret = lttng_poll_add(&events, client_sock, LPOLLIN | LPOLLPRI);
2611 if (ret < 0) {
2612 goto error;
2613 }
2614
2615 /* Add thread quit pipe */
2616 ret = lttng_poll_add(&events, thread_quit_pipe_fd, LPOLLIN | LPOLLERR);
2617 if (ret < 0) {
2618 goto error;
2619 }
2620
2621 /* Set state as running. */
2622 set_thread_status(true);
2623 pthread_cleanup_pop(0);
2624
2625 /* This testpoint is after we signal readiness to the parent. */
2626 if (testpoint(sessiond_thread_manage_clients)) {
2627 goto error;
2628 }
2629
2630 if (testpoint(sessiond_thread_manage_clients_before_loop)) {
2631 goto error;
2632 }
2633
2634 health_code_update();
2635
2636 while (1) {
2637 const struct cmd_completion_handler *cmd_completion_handler;
2638
2639 cmd_ctx.creds = (lttng_sock_cred) {
2640 .uid = UINT32_MAX,
2641 .gid = UINT32_MAX,
2642 };
2643 cmd_ctx.session = NULL;
2644 lttng_payload_clear(&cmd_ctx.reply_payload);
2645 cmd_ctx.lttng_msg_size = 0;
2646
2647 DBG("Accepting client command ...");
2648
2649 /* Inifinite blocking call, waiting for transmission */
2650 restart:
2651 health_poll_entry();
2652 ret = lttng_poll_wait(&events, -1);
2653 health_poll_exit();
2654 if (ret < 0) {
2655 /*
2656 * Restart interrupted system call.
2657 */
2658 if (errno == EINTR) {
2659 goto restart;
2660 }
2661 goto error;
2662 }
2663
2664 nb_fd = ret;
2665
2666 for (i = 0; i < nb_fd; i++) {
2667 revents = LTTNG_POLL_GETEV(&events, i);
2668 pollfd = LTTNG_POLL_GETFD(&events, i);
2669
2670 health_code_update();
2671
2672 if (pollfd == thread_quit_pipe_fd) {
2673 err = 0;
2674 goto exit;
2675 } else {
2676 /* Event on the registration socket */
2677 if (revents & LPOLLIN) {
2678 continue;
2679 } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
2680 ERR("Client socket poll error");
2681 goto error;
2682 } else {
2683 ERR("Unexpected poll events %u for sock %d", revents, pollfd);
2684 goto error;
2685 }
2686 }
2687 }
2688
2689 DBG("Wait for client response");
2690
2691 health_code_update();
2692
2693 sock = lttcomm_accept_unix_sock(client_sock);
2694 if (sock < 0) {
2695 goto error;
2696 }
2697
2698 /*
2699 * Set the CLOEXEC flag. Return code is useless because either way, the
2700 * show must go on.
2701 */
2702 (void) utils_set_fd_cloexec(sock);
2703
2704 /* Set socket option for credentials retrieval */
2705 ret = lttcomm_setsockopt_creds_unix_sock(sock);
2706 if (ret < 0) {
2707 goto error;
2708 }
2709
2710 health_code_update();
2711
2712 /*
2713 * Data is received from the lttng client. The struct
2714 * lttcomm_session_msg (lsm) contains the command and data request of
2715 * the client.
2716 */
2717 DBG("Receiving data from client ...");
2718 ret = lttcomm_recv_creds_unix_sock(sock, &cmd_ctx.lsm,
2719 sizeof(struct lttcomm_session_msg), &cmd_ctx.creds);
2720 if (ret != sizeof(struct lttcomm_session_msg)) {
2721 DBG("Incomplete recv() from client... continuing");
2722 ret = close(sock);
2723 if (ret) {
2724 PERROR("close");
2725 }
2726 sock = -1;
2727 continue;
2728 }
2729
2730 health_code_update();
2731
2732 // TODO: Validate cmd_ctx including sanity check for
2733 // security purpose.
2734
2735 rcu_thread_online();
2736 /*
2737 * This function dispatch the work to the kernel or userspace tracer
2738 * libs and fill the lttcomm_lttng_msg data structure of all the needed
2739 * informations for the client. The command context struct contains
2740 * everything this function may needs.
2741 */
2742 ret = process_client_msg(&cmd_ctx, &sock, &sock_error);
2743 rcu_thread_offline();
2744 if (ret < 0) {
2745 if (sock >= 0) {
2746 ret = close(sock);
2747 if (ret) {
2748 PERROR("close");
2749 }
2750 }
2751 sock = -1;
2752 /*
2753 * TODO: Inform client somehow of the fatal error. At
2754 * this point, ret < 0 means that a zmalloc failed
2755 * (ENOMEM). Error detected but still accept
2756 * command, unless a socket error has been
2757 * detected.
2758 */
2759 continue;
2760 }
2761
2762 if (ret < LTTNG_OK || ret >= LTTNG_ERR_NR) {
2763 WARN("Command returned an invalid status code, returning unknown error: "
2764 "command type = %s (%d), ret = %d",
2765 lttcomm_sessiond_command_str(cmd_ctx.lsm.cmd_type),
2766 cmd_ctx.lsm.cmd_type, ret);
2767 ret = LTTNG_ERR_UNK;
2768 }
2769
2770 cmd_completion_handler = cmd_pop_completion_handler();
2771 if (cmd_completion_handler) {
2772 enum lttng_error_code completion_code;
2773
2774 completion_code = cmd_completion_handler->run(
2775 cmd_completion_handler->data);
2776 if (completion_code != LTTNG_OK) {
2777 continue;
2778 }
2779 }
2780
2781 health_code_update();
2782
2783 if (sock >= 0) {
2784 struct lttng_payload_view view =
2785 lttng_payload_view_from_payload(
2786 &cmd_ctx.reply_payload,
2787 0, -1);
2788 struct lttcomm_lttng_msg *llm = (typeof(
2789 llm)) cmd_ctx.reply_payload.buffer.data;
2790
2791 LTTNG_ASSERT(cmd_ctx.reply_payload.buffer.size >= sizeof(*llm));
2792 LTTNG_ASSERT(cmd_ctx.lttng_msg_size == cmd_ctx.reply_payload.buffer.size);
2793
2794 llm->fd_count = lttng_payload_view_get_fd_handle_count(&view);
2795
2796 DBG("Sending response (size: %d, retcode: %s (%d))",
2797 cmd_ctx.lttng_msg_size,
2798 lttng_strerror(-llm->ret_code),
2799 llm->ret_code);
2800 ret = send_unix_sock(sock, &view);
2801 if (ret < 0) {
2802 ERR("Failed to send data back to client");
2803 }
2804
2805 /* End of transmission */
2806 ret = close(sock);
2807 if (ret) {
2808 PERROR("close");
2809 }
2810 }
2811 sock = -1;
2812
2813 health_code_update();
2814 }
2815
2816 exit:
2817 error:
2818 if (sock >= 0) {
2819 ret = close(sock);
2820 if (ret) {
2821 PERROR("close");
2822 }
2823 }
2824
2825 lttng_poll_clean(&events);
2826
2827 error_listen:
2828 error_create_poll:
2829 unlink(the_config.client_unix_sock_path.value);
2830 ret = close(client_sock);
2831 if (ret) {
2832 PERROR("close");
2833 }
2834
2835 if (err) {
2836 health_error();
2837 ERR("Health error occurred in %s", __func__);
2838 }
2839
2840 health_unregister(the_health_sessiond);
2841
2842 DBG("Client thread dying");
2843 lttng_payload_reset(&cmd_ctx.reply_payload);
2844 rcu_unregister_thread();
2845 return NULL;
2846 }
2847
2848 static
2849 bool shutdown_client_thread(void *thread_data)
2850 {
2851 struct lttng_pipe *client_quit_pipe = thread_data;
2852 const int write_fd = lttng_pipe_get_writefd(client_quit_pipe);
2853
2854 return notify_thread_pipe(write_fd) == 1;
2855 }
2856
2857 struct lttng_thread *launch_client_thread(void)
2858 {
2859 bool thread_running;
2860 struct lttng_pipe *client_quit_pipe;
2861 struct lttng_thread *thread = NULL;
2862 int client_sock_fd = -1;
2863
2864 sem_init(&thread_state.ready, 0, 0);
2865 client_quit_pipe = lttng_pipe_open(FD_CLOEXEC);
2866 if (!client_quit_pipe) {
2867 goto error;
2868 }
2869
2870 client_sock_fd = create_client_sock();
2871 if (client_sock_fd < 0) {
2872 goto error;
2873 }
2874
2875 thread_state.client_sock = client_sock_fd;
2876 thread = lttng_thread_create("Client management",
2877 thread_manage_clients,
2878 shutdown_client_thread,
2879 cleanup_client_thread,
2880 client_quit_pipe);
2881 if (!thread) {
2882 goto error;
2883 }
2884 /* The client thread now owns the client sock fd and the quit pipe. */
2885 client_sock_fd = -1;
2886 client_quit_pipe = NULL;
2887
2888 /*
2889 * This thread is part of the threads that need to be fully
2890 * initialized before the session daemon is marked as "ready".
2891 */
2892 thread_running = wait_thread_status();
2893 if (!thread_running) {
2894 goto error;
2895 }
2896 return thread;
2897 error:
2898 if (client_sock_fd >= 0) {
2899 if (close(client_sock_fd)) {
2900 PERROR("Failed to close client socket");
2901 }
2902 }
2903 lttng_thread_put(thread);
2904 cleanup_client_thread(client_quit_pipe);
2905 return NULL;
2906 }
LTTng 2.0 tools and control repository
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