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[lttng-tools.git] / src / bin / lttng-sessiond / client.cpp
1 /*
2 * Copyright (C) 2011 EfficiOS Inc.
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 "agent-thread.hpp"
11 #include "clear.hpp"
12 #include "client.hpp"
13 #include "cmd.hpp"
14 #include "health-sessiond.hpp"
15 #include "kernel.hpp"
16 #include "lttng-sessiond.hpp"
17 #include "manage-consumer.hpp"
18 #include "save.hpp"
19 #include "testpoint.hpp"
20 #include "utils.hpp"
21
22 #include <common/buffer-view.hpp>
23 #include <common/compat/getenv.hpp>
24 #include <common/compat/socket.hpp>
25 #include <common/dynamic-array.hpp>
26 #include <common/dynamic-buffer.hpp>
27 #include <common/exception.hpp>
28 #include <common/fd-handle.hpp>
29 #include <common/payload-view.hpp>
30 #include <common/payload.hpp>
31 #include <common/sessiond-comm/sessiond-comm.hpp>
32 #include <common/tracker.hpp>
33 #include <common/unix.hpp>
34 #include <common/utils.hpp>
35
36 #include <lttng/error-query-internal.hpp>
37 #include <lttng/event-internal.hpp>
38 #include <lttng/lttng.h>
39 #include <lttng/session-descriptor-internal.hpp>
40 #include <lttng/session-internal.hpp>
41 #include <lttng/userspace-probe-internal.hpp>
42
43 #include <fcntl.h>
44 #include <pthread.h>
45 #include <signal.h>
46 #include <stddef.h>
47 #include <stdint.h>
48 #include <sys/stat.h>
49 #include <unistd.h>
50
51 namespace {
52 bool is_root;
53
54 struct thread_state {
55 sem_t ready;
56 bool running;
57 int client_sock;
58 } thread_state;
59 } /* namespace */
60
61 static void set_thread_status(bool running)
62 {
63 DBG("Marking client thread's state as %s", running ? "running" : "error");
64 thread_state.running = running;
65 sem_post(&thread_state.ready);
66 }
67
68 static bool wait_thread_status()
69 {
70 DBG("Waiting for client thread to be ready");
71 sem_wait(&thread_state.ready);
72 if (thread_state.running) {
73 DBG("Client thread is ready");
74 } else {
75 ERR("Initialization of client thread failed");
76 }
77
78 return thread_state.running;
79 }
80
81 /*
82 * Setup the outgoing data buffer for the response (llm) by allocating the
83 * right amount of memory and copying the original information from the lsm
84 * structure.
85 *
86 * Return 0 on success, negative value on error.
87 */
88 static int setup_lttng_msg(struct command_ctx *cmd_ctx,
89 const void *payload_buf,
90 size_t payload_len,
91 const void *cmd_header_buf,
92 size_t cmd_header_len)
93 {
94 int ret = 0;
95 const size_t header_len = sizeof(struct lttcomm_lttng_msg);
96 const size_t total_msg_size = header_len + cmd_header_len + payload_len;
97 lttcomm_lttng_msg llm{};
98
99 llm.cmd_type = cmd_ctx->lsm.cmd_type;
100 llm.pid = (uint32_t) cmd_ctx->lsm.domain.attr.pid;
101 llm.cmd_header_size = (uint32_t) cmd_header_len;
102 llm.data_size = (uint32_t) payload_len;
103
104 ret = lttng_dynamic_buffer_set_size(&cmd_ctx->reply_payload.buffer, 0);
105 if (ret) {
106 goto end;
107 }
108
109 lttng_dynamic_pointer_array_clear(&cmd_ctx->reply_payload._fd_handles);
110
111 cmd_ctx->lttng_msg_size = total_msg_size;
112
113 /* Append reply header. */
114 ret = lttng_dynamic_buffer_append(&cmd_ctx->reply_payload.buffer, &llm, sizeof(llm));
115 if (ret) {
116 goto end;
117 }
118
119 /* Append command header. */
120 if (cmd_header_len) {
121 ret = lttng_dynamic_buffer_append(
122 &cmd_ctx->reply_payload.buffer, cmd_header_buf, cmd_header_len);
123 if (ret) {
124 goto end;
125 }
126 }
127
128 /* Append payload. */
129 if (payload_len) {
130 ret = lttng_dynamic_buffer_append(
131 &cmd_ctx->reply_payload.buffer, payload_buf, payload_len);
132 if (ret) {
133 goto end;
134 }
135 }
136
137 end:
138 return ret;
139 }
140
141 static int setup_empty_lttng_msg(struct command_ctx *cmd_ctx)
142 {
143 int ret;
144 const struct lttcomm_lttng_msg llm = {};
145
146 ret = lttng_dynamic_buffer_set_size(&cmd_ctx->reply_payload.buffer, 0);
147 if (ret) {
148 goto end;
149 }
150
151 /* Append place-holder reply header. */
152 ret = lttng_dynamic_buffer_append(&cmd_ctx->reply_payload.buffer, &llm, sizeof(llm));
153 if (ret) {
154 goto end;
155 }
156
157 cmd_ctx->lttng_msg_size = sizeof(llm);
158 end:
159 return ret;
160 }
161
162 static void update_lttng_msg(struct command_ctx *cmd_ctx, size_t cmd_header_len, size_t payload_len)
163 {
164 const size_t header_len = sizeof(struct lttcomm_lttng_msg);
165 const size_t total_msg_size = header_len + cmd_header_len + payload_len;
166 struct lttcomm_lttng_msg *p_llm;
167 lttcomm_lttng_msg llm{};
168
169 llm.cmd_type = cmd_ctx->lsm.cmd_type;
170 llm.pid = (uint32_t) cmd_ctx->lsm.domain.attr.pid;
171 llm.cmd_header_size = (uint32_t) cmd_header_len;
172 llm.data_size = (uint32_t) payload_len;
173
174 LTTNG_ASSERT(cmd_ctx->reply_payload.buffer.size >= sizeof(llm));
175
176 p_llm = (typeof(p_llm)) cmd_ctx->reply_payload.buffer.data;
177
178 /* Update existing header. */
179 memcpy(p_llm, &llm, sizeof(llm));
180
181 cmd_ctx->lttng_msg_size = total_msg_size;
182 }
183
184 /*
185 * Start the thread_manage_consumer. This must be done after a lttng-consumerd
186 * exec or it will fail.
187 */
188 static int spawn_consumer_thread(struct consumer_data *consumer_data)
189 {
190 return launch_consumer_management_thread(consumer_data) ? 0 : -1;
191 }
192
193 /*
194 * Fork and exec a consumer daemon (consumerd).
195 *
196 * Return pid if successful else -1.
197 */
198 static pid_t spawn_consumerd(struct consumer_data *consumer_data)
199 {
200 int ret;
201 pid_t pid;
202 const char *consumer_to_use;
203 const char *verbosity;
204 struct stat st;
205
206 DBG("Spawning consumerd");
207
208 pid = fork();
209 if (pid == 0) {
210 /*
211 * Exec consumerd.
212 */
213 if (the_config.verbose_consumer) {
214 verbosity = "--verbose";
215 } else if (lttng_opt_quiet) {
216 verbosity = "--quiet";
217 } else {
218 verbosity = "";
219 }
220
221 switch (consumer_data->type) {
222 case LTTNG_CONSUMER_KERNEL:
223 /*
224 * Find out which consumerd to execute. We will first try the
225 * 64-bit path, then the sessiond's installation directory, and
226 * fallback on the 32-bit one,
227 */
228 DBG3("Looking for a kernel consumer at these locations:");
229 DBG3(" 1) %s", the_config.consumerd64_bin_path.value ?: "NULL");
230 DBG3(" 2) %s/%s", INSTALL_BIN_PATH, DEFAULT_CONSUMERD_FILE);
231 DBG3(" 3) %s", the_config.consumerd32_bin_path.value ?: "NULL");
232 if (stat(the_config.consumerd64_bin_path.value, &st) == 0) {
233 DBG3("Found location #1");
234 consumer_to_use = the_config.consumerd64_bin_path.value;
235 } else if (stat(INSTALL_BIN_PATH "/" DEFAULT_CONSUMERD_FILE, &st) == 0) {
236 DBG3("Found location #2");
237 consumer_to_use = INSTALL_BIN_PATH "/" DEFAULT_CONSUMERD_FILE;
238 } else if (the_config.consumerd32_bin_path.value &&
239 stat(the_config.consumerd32_bin_path.value, &st) == 0) {
240 DBG3("Found location #3");
241 consumer_to_use = the_config.consumerd32_bin_path.value;
242 } else {
243 DBG("Could not find any valid consumerd executable");
244 ret = -EINVAL;
245 goto error;
246 }
247 DBG("Using kernel consumer at: %s", consumer_to_use);
248 (void) execl(consumer_to_use,
249 "lttng-consumerd",
250 verbosity,
251 "-k",
252 "--consumerd-cmd-sock",
253 consumer_data->cmd_unix_sock_path,
254 "--consumerd-err-sock",
255 consumer_data->err_unix_sock_path,
256 "--group",
257 the_config.tracing_group_name.value,
258 NULL);
259 break;
260 case LTTNG_CONSUMER64_UST:
261 {
262 if (the_config.consumerd64_lib_dir.value) {
263 const char *tmp;
264 size_t tmplen;
265 char *tmpnew;
266
267 tmp = lttng_secure_getenv("LD_LIBRARY_PATH");
268 if (!tmp) {
269 tmp = "";
270 }
271 tmplen = strlen(the_config.consumerd64_lib_dir.value) + 1 /* : */ +
272 strlen(tmp);
273 tmpnew = zmalloc<char>(tmplen + 1 /* \0 */);
274 if (!tmpnew) {
275 ret = -ENOMEM;
276 goto error;
277 }
278 strcat(tmpnew, the_config.consumerd64_lib_dir.value);
279 if (tmp[0] != '\0') {
280 strcat(tmpnew, ":");
281 strcat(tmpnew, tmp);
282 }
283 ret = setenv("LD_LIBRARY_PATH", tmpnew, 1);
284 free(tmpnew);
285 if (ret) {
286 ret = -errno;
287 goto error;
288 }
289 }
290 DBG("Using 64-bit UST consumer at: %s",
291 the_config.consumerd64_bin_path.value);
292 (void) execl(the_config.consumerd64_bin_path.value,
293 "lttng-consumerd",
294 verbosity,
295 "-u",
296 "--consumerd-cmd-sock",
297 consumer_data->cmd_unix_sock_path,
298 "--consumerd-err-sock",
299 consumer_data->err_unix_sock_path,
300 "--group",
301 the_config.tracing_group_name.value,
302 NULL);
303 break;
304 }
305 case LTTNG_CONSUMER32_UST:
306 {
307 if (the_config.consumerd32_lib_dir.value) {
308 const char *tmp;
309 size_t tmplen;
310 char *tmpnew;
311
312 tmp = lttng_secure_getenv("LD_LIBRARY_PATH");
313 if (!tmp) {
314 tmp = "";
315 }
316 tmplen = strlen(the_config.consumerd32_lib_dir.value) + 1 /* : */ +
317 strlen(tmp);
318 tmpnew = zmalloc<char>(tmplen + 1 /* \0 */);
319 if (!tmpnew) {
320 ret = -ENOMEM;
321 goto error;
322 }
323 strcat(tmpnew, the_config.consumerd32_lib_dir.value);
324 if (tmp[0] != '\0') {
325 strcat(tmpnew, ":");
326 strcat(tmpnew, tmp);
327 }
328 ret = setenv("LD_LIBRARY_PATH", tmpnew, 1);
329 free(tmpnew);
330 if (ret) {
331 ret = -errno;
332 goto error;
333 }
334 }
335 DBG("Using 32-bit UST consumer at: %s",
336 the_config.consumerd32_bin_path.value);
337 (void) execl(the_config.consumerd32_bin_path.value,
338 "lttng-consumerd",
339 verbosity,
340 "-u",
341 "--consumerd-cmd-sock",
342 consumer_data->cmd_unix_sock_path,
343 "--consumerd-err-sock",
344 consumer_data->err_unix_sock_path,
345 "--group",
346 the_config.tracing_group_name.value,
347 NULL);
348 break;
349 }
350 default:
351 ERR("unknown consumer type");
352 errno = 0;
353 }
354 if (errno != 0) {
355 PERROR("Consumer execl()");
356 }
357 /* Reaching this point, we got a failure on our execl(). */
358 exit(EXIT_FAILURE);
359 } else if (pid > 0) {
360 ret = pid;
361 } else {
362 PERROR("start consumer fork");
363 ret = -errno;
364 }
365 error:
366 return ret;
367 }
368
369 /*
370 * Spawn the consumerd daemon and session daemon thread.
371 */
372 static int start_consumerd(struct consumer_data *consumer_data)
373 {
374 int ret;
375
376 /*
377 * Set the listen() state on the socket since there is a possible race
378 * between the exec() of the consumer daemon and this call if place in the
379 * consumer thread. See bug #366 for more details.
380 */
381 ret = lttcomm_listen_unix_sock(consumer_data->err_sock);
382 if (ret < 0) {
383 goto error;
384 }
385
386 pthread_mutex_lock(&consumer_data->pid_mutex);
387 if (consumer_data->pid != 0) {
388 pthread_mutex_unlock(&consumer_data->pid_mutex);
389 goto end;
390 }
391
392 ret = spawn_consumerd(consumer_data);
393 if (ret < 0) {
394 ERR("Spawning consumerd failed");
395 pthread_mutex_unlock(&consumer_data->pid_mutex);
396 goto error;
397 }
398
399 /* Setting up the consumer_data pid */
400 consumer_data->pid = ret;
401 DBG2("Consumer pid %d", consumer_data->pid);
402 pthread_mutex_unlock(&consumer_data->pid_mutex);
403
404 DBG2("Spawning consumer control thread");
405 ret = spawn_consumer_thread(consumer_data);
406 if (ret < 0) {
407 ERR("Fatal error spawning consumer control thread");
408 goto error;
409 }
410
411 end:
412 return 0;
413
414 error:
415 /* Cleanup already created sockets on error. */
416 if (consumer_data->err_sock >= 0) {
417 int err;
418
419 err = close(consumer_data->err_sock);
420 if (err < 0) {
421 PERROR("close consumer data error socket");
422 }
423 }
424 return ret;
425 }
426
427 /*
428 * Copy consumer output from the tracing session to the domain session. The
429 * function also applies the right modification on a per domain basis for the
430 * trace files destination directory.
431 */
432 static int copy_session_consumer(int domain, struct ltt_session *session)
433 {
434 int ret;
435 const char *dir_name;
436 struct consumer_output *consumer;
437
438 LTTNG_ASSERT(session);
439 LTTNG_ASSERT(session->consumer);
440
441 switch (domain) {
442 case LTTNG_DOMAIN_KERNEL:
443 DBG3("Copying tracing session consumer output in kernel session");
444 /*
445 * XXX: We should audit the session creation and what this function
446 * does "extra" in order to avoid a destroy since this function is used
447 * in the domain session creation (kernel and ust) only. Same for UST
448 * domain.
449 */
450 if (session->kernel_session->consumer) {
451 consumer_output_put(session->kernel_session->consumer);
452 }
453 session->kernel_session->consumer = consumer_copy_output(session->consumer);
454 /* Ease our life a bit for the next part */
455 consumer = session->kernel_session->consumer;
456 dir_name = DEFAULT_KERNEL_TRACE_DIR;
457 break;
458 case LTTNG_DOMAIN_JUL:
459 case LTTNG_DOMAIN_LOG4J:
460 case LTTNG_DOMAIN_PYTHON:
461 case LTTNG_DOMAIN_UST:
462 DBG3("Copying tracing session consumer output in UST session");
463 if (session->ust_session->consumer) {
464 consumer_output_put(session->ust_session->consumer);
465 }
466 session->ust_session->consumer = consumer_copy_output(session->consumer);
467 /* Ease our life a bit for the next part */
468 consumer = session->ust_session->consumer;
469 dir_name = DEFAULT_UST_TRACE_DIR;
470 break;
471 default:
472 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
473 goto error;
474 }
475
476 /* Append correct directory to subdir */
477 ret = lttng_strncpy(consumer->domain_subdir, dir_name, sizeof(consumer->domain_subdir));
478 if (ret) {
479 ret = LTTNG_ERR_UNK;
480 goto error;
481 }
482 DBG3("Copy session consumer subdir %s", consumer->domain_subdir);
483 ret = LTTNG_OK;
484
485 error:
486 return ret;
487 }
488
489 /*
490 * Create an UST session and add it to the session ust list.
491 */
492 static int create_ust_session(struct ltt_session *session, const struct lttng_domain *domain)
493 {
494 int ret;
495 struct ltt_ust_session *lus = nullptr;
496
497 LTTNG_ASSERT(session);
498 LTTNG_ASSERT(domain);
499 LTTNG_ASSERT(session->consumer);
500
501 switch (domain->type) {
502 case LTTNG_DOMAIN_JUL:
503 case LTTNG_DOMAIN_LOG4J:
504 case LTTNG_DOMAIN_PYTHON:
505 case LTTNG_DOMAIN_UST:
506 break;
507 default:
508 ERR("Unknown UST domain on create session %d", domain->type);
509 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
510 goto error;
511 }
512
513 DBG("Creating UST session");
514
515 lus = trace_ust_create_session(session->id);
516 if (lus == nullptr) {
517 ret = LTTNG_ERR_UST_SESS_FAIL;
518 goto error;
519 }
520
521 lus->uid = session->uid;
522 lus->gid = session->gid;
523 lus->output_traces = session->output_traces;
524 lus->snapshot_mode = session->snapshot_mode;
525 lus->live_timer_interval = session->live_timer;
526 session->ust_session = lus;
527 if (session->shm_path[0]) {
528 strncpy(lus->root_shm_path, session->shm_path, sizeof(lus->root_shm_path));
529 lus->root_shm_path[sizeof(lus->root_shm_path) - 1] = '\0';
530 strncpy(lus->shm_path, session->shm_path, sizeof(lus->shm_path));
531 lus->shm_path[sizeof(lus->shm_path) - 1] = '\0';
532 strncat(lus->shm_path, "/ust", sizeof(lus->shm_path) - strlen(lus->shm_path) - 1);
533 }
534 /* Copy session output to the newly created UST session */
535 ret = copy_session_consumer(domain->type, session);
536 if (ret != LTTNG_OK) {
537 goto error;
538 }
539
540 return LTTNG_OK;
541
542 error:
543 free(lus);
544 session->ust_session = nullptr;
545 return ret;
546 }
547
548 /*
549 * Create a kernel tracer session then create the default channel.
550 */
551 static int create_kernel_session(struct ltt_session *session)
552 {
553 int ret;
554
555 DBG("Creating kernel session");
556
557 ret = kernel_create_session(session);
558 if (ret < 0) {
559 ret = LTTNG_ERR_KERN_SESS_FAIL;
560 goto error_create;
561 }
562
563 /* Code flow safety */
564 LTTNG_ASSERT(session->kernel_session);
565
566 /* Copy session output to the newly created Kernel session */
567 ret = copy_session_consumer(LTTNG_DOMAIN_KERNEL, session);
568 if (ret != LTTNG_OK) {
569 goto error;
570 }
571
572 session->kernel_session->uid = session->uid;
573 session->kernel_session->gid = session->gid;
574 session->kernel_session->output_traces = session->output_traces;
575 session->kernel_session->snapshot_mode = session->snapshot_mode;
576 session->kernel_session->is_live_session = session->live_timer != 0;
577
578 return LTTNG_OK;
579
580 error:
581 trace_kernel_destroy_session(session->kernel_session);
582 session->kernel_session = nullptr;
583 error_create:
584 return ret;
585 }
586
587 /*
588 * Count number of session permitted by uid/gid.
589 */
590 static unsigned int lttng_sessions_count(uid_t uid, gid_t gid __attribute__((unused)))
591 {
592 unsigned int i = 0;
593 struct ltt_session *session;
594 const struct ltt_session_list *session_list = session_get_list();
595
596 DBG("Counting number of available session for UID %d", uid);
597 cds_list_for_each_entry (session, &session_list->head, list) {
598 if (!session_get(session)) {
599 continue;
600 }
601 session_lock(session);
602 /* Only count the sessions the user can control. */
603 if (session_access_ok(session, uid) && !session->destroyed) {
604 i++;
605 }
606 session_unlock(session);
607 session_put(session);
608 }
609 return i;
610 }
611
612 static enum lttng_error_code receive_lttng_trigger(struct command_ctx *cmd_ctx,
613 int sock,
614 int *sock_error,
615 struct lttng_trigger **_trigger)
616 {
617 int ret;
618 size_t trigger_len;
619 ssize_t sock_recv_len;
620 enum lttng_error_code ret_code;
621 struct lttng_payload trigger_payload;
622 struct lttng_trigger *trigger = nullptr;
623
624 lttng_payload_init(&trigger_payload);
625 trigger_len = (size_t) cmd_ctx->lsm.u.trigger.length;
626 ret = lttng_dynamic_buffer_set_size(&trigger_payload.buffer, trigger_len);
627 if (ret) {
628 ret_code = LTTNG_ERR_NOMEM;
629 goto end;
630 }
631
632 sock_recv_len = lttcomm_recv_unix_sock(sock, trigger_payload.buffer.data, trigger_len);
633 if (sock_recv_len < 0 || sock_recv_len != trigger_len) {
634 ERR("Failed to receive trigger in command payload");
635 *sock_error = 1;
636 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
637 goto end;
638 }
639
640 /* Receive fds, if any. */
641 if (cmd_ctx->lsm.fd_count > 0) {
642 sock_recv_len = lttcomm_recv_payload_fds_unix_sock(
643 sock, cmd_ctx->lsm.fd_count, &trigger_payload);
644 if (sock_recv_len > 0 && sock_recv_len != cmd_ctx->lsm.fd_count * sizeof(int)) {
645 ERR("Failed to receive all file descriptors for trigger in command payload: expected fd count = %u, ret = %d",
646 cmd_ctx->lsm.fd_count,
647 (int) ret);
648 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
649 *sock_error = 1;
650 goto end;
651 } else if (sock_recv_len <= 0) {
652 ERR("Failed to receive file descriptors for trigger in command payload: expected fd count = %u, ret = %d",
653 cmd_ctx->lsm.fd_count,
654 (int) ret);
655 ret_code = LTTNG_ERR_FATAL;
656 *sock_error = 1;
657 goto end;
658 }
659 }
660
661 /* Deserialize trigger. */
662 {
663 struct lttng_payload_view view =
664 lttng_payload_view_from_payload(&trigger_payload, 0, -1);
665
666 if (lttng_trigger_create_from_payload(&view, &trigger) != trigger_len) {
667 ERR("Invalid trigger received as part of command payload");
668 ret_code = LTTNG_ERR_INVALID_TRIGGER;
669 lttng_trigger_put(trigger);
670 goto end;
671 }
672 }
673
674 *_trigger = trigger;
675 ret_code = LTTNG_OK;
676
677 end:
678 lttng_payload_reset(&trigger_payload);
679 return ret_code;
680 }
681
682 static enum lttng_error_code receive_lttng_error_query(struct command_ctx *cmd_ctx,
683 int sock,
684 int *sock_error,
685 struct lttng_error_query **_query)
686 {
687 int ret;
688 size_t query_len;
689 ssize_t sock_recv_len;
690 enum lttng_error_code ret_code;
691 struct lttng_payload query_payload;
692 struct lttng_error_query *query = nullptr;
693
694 lttng_payload_init(&query_payload);
695 query_len = (size_t) cmd_ctx->lsm.u.error_query.length;
696 ret = lttng_dynamic_buffer_set_size(&query_payload.buffer, query_len);
697 if (ret) {
698 ret_code = LTTNG_ERR_NOMEM;
699 goto end;
700 }
701
702 sock_recv_len = lttcomm_recv_unix_sock(sock, query_payload.buffer.data, query_len);
703 if (sock_recv_len < 0 || sock_recv_len != query_len) {
704 ERR("Failed to receive error query in command payload");
705 *sock_error = 1;
706 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
707 goto end;
708 }
709
710 /* Receive fds, if any. */
711 if (cmd_ctx->lsm.fd_count > 0) {
712 sock_recv_len = lttcomm_recv_payload_fds_unix_sock(
713 sock, cmd_ctx->lsm.fd_count, &query_payload);
714 if (sock_recv_len > 0 && sock_recv_len != cmd_ctx->lsm.fd_count * sizeof(int)) {
715 ERR("Failed to receive all file descriptors for error query in command payload: expected fd count = %u, ret = %d",
716 cmd_ctx->lsm.fd_count,
717 (int) ret);
718 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
719 *sock_error = 1;
720 goto end;
721 } else if (sock_recv_len <= 0) {
722 ERR("Failed to receive file descriptors for error query in command payload: expected fd count = %u, ret = %d",
723 cmd_ctx->lsm.fd_count,
724 (int) ret);
725 ret_code = LTTNG_ERR_FATAL;
726 *sock_error = 1;
727 goto end;
728 }
729 }
730
731 /* Deserialize error query. */
732 {
733 struct lttng_payload_view view =
734 lttng_payload_view_from_payload(&query_payload, 0, -1);
735
736 if (lttng_error_query_create_from_payload(&view, &query) != query_len) {
737 ERR("Invalid error query received as part of command payload");
738 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
739 goto end;
740 }
741 }
742
743 *_query = query;
744 ret_code = LTTNG_OK;
745
746 end:
747 lttng_payload_reset(&query_payload);
748 return ret_code;
749 }
750
751 static enum lttng_error_code receive_lttng_event(struct command_ctx *cmd_ctx,
752 int sock,
753 int *sock_error,
754 struct lttng_event **out_event,
755 char **out_filter_expression,
756 struct lttng_bytecode **out_bytecode,
757 struct lttng_event_exclusion **out_exclusion)
758 {
759 int ret;
760 size_t event_len;
761 ssize_t sock_recv_len;
762 enum lttng_error_code ret_code;
763 struct lttng_payload event_payload;
764 struct lttng_event *local_event = nullptr;
765 char *local_filter_expression = nullptr;
766 struct lttng_bytecode *local_bytecode = nullptr;
767 struct lttng_event_exclusion *local_exclusion = nullptr;
768
769 lttng_payload_init(&event_payload);
770 if (cmd_ctx->lsm.cmd_type == LTTCOMM_SESSIOND_COMMAND_ENABLE_EVENT) {
771 event_len = (size_t) cmd_ctx->lsm.u.enable.length;
772 } else if (cmd_ctx->lsm.cmd_type == LTTCOMM_SESSIOND_COMMAND_DISABLE_EVENT) {
773 event_len = (size_t) cmd_ctx->lsm.u.disable.length;
774 } else {
775 abort();
776 }
777
778 ret = lttng_dynamic_buffer_set_size(&event_payload.buffer, event_len);
779 if (ret) {
780 ret_code = LTTNG_ERR_NOMEM;
781 goto end;
782 }
783
784 sock_recv_len = lttcomm_recv_unix_sock(sock, event_payload.buffer.data, event_len);
785 if (sock_recv_len < 0 || sock_recv_len != event_len) {
786 ERR("Failed to receive event in command payload");
787 *sock_error = 1;
788 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
789 goto end;
790 }
791
792 /* Receive fds, if any. */
793 if (cmd_ctx->lsm.fd_count > 0) {
794 sock_recv_len = lttcomm_recv_payload_fds_unix_sock(
795 sock, cmd_ctx->lsm.fd_count, &event_payload);
796 if (sock_recv_len > 0 && sock_recv_len != cmd_ctx->lsm.fd_count * sizeof(int)) {
797 ERR("Failed to receive all file descriptors for event in command payload: expected fd count = %u, ret = %d",
798 cmd_ctx->lsm.fd_count,
799 (int) ret);
800 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
801 *sock_error = 1;
802 goto end;
803 } else if (sock_recv_len <= 0) {
804 ERR("Failed to receive file descriptors for event in command payload: expected fd count = %u, ret = %d",
805 cmd_ctx->lsm.fd_count,
806 (int) ret);
807 ret_code = LTTNG_ERR_FATAL;
808 *sock_error = 1;
809 goto end;
810 }
811 }
812
813 /* Deserialize event. */
814 {
815 ssize_t len;
816 struct lttng_payload_view event_view =
817 lttng_payload_view_from_payload(&event_payload, 0, -1);
818
819 len = lttng_event_create_from_payload(&event_view,
820 &local_event,
821 &local_exclusion,
822 &local_filter_expression,
823 &local_bytecode);
824
825 if (len < 0) {
826 ERR("Failed to create an event from the received buffer");
827 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
828 goto end;
829 }
830
831 if (len != event_len) {
832 ERR("Userspace probe location from the received buffer is not the advertised length: header length = %zu" PRIu32
833 ", payload length = %zd",
834 event_len,
835 len);
836 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
837 goto end;
838 }
839 }
840
841 *out_event = local_event;
842 *out_exclusion = local_exclusion;
843 *out_filter_expression = local_filter_expression;
844 *out_bytecode = local_bytecode;
845 local_event = nullptr;
846 local_exclusion = nullptr;
847 local_filter_expression = nullptr;
848 local_bytecode = nullptr;
849
850 ret_code = LTTNG_OK;
851
852 end:
853 lttng_payload_reset(&event_payload);
854 lttng_event_destroy(local_event);
855 free(local_filter_expression);
856 free(local_bytecode);
857 free(local_exclusion);
858 return ret_code;
859 }
860
861 static enum lttng_error_code
862 receive_lttng_event_context(const struct command_ctx *cmd_ctx,
863 int sock,
864 int *sock_error,
865 struct lttng_event_context **out_event_context)
866 {
867 int ret;
868 const size_t event_context_len = (size_t) cmd_ctx->lsm.u.context.length;
869 ssize_t sock_recv_len;
870 enum lttng_error_code ret_code;
871 struct lttng_payload event_context_payload;
872 struct lttng_event_context *context = nullptr;
873
874 lttng_payload_init(&event_context_payload);
875
876 ret = lttng_dynamic_buffer_set_size(&event_context_payload.buffer, event_context_len);
877 if (ret) {
878 ret_code = LTTNG_ERR_NOMEM;
879 goto end;
880 }
881
882 sock_recv_len =
883 lttcomm_recv_unix_sock(sock, event_context_payload.buffer.data, event_context_len);
884 if (sock_recv_len < 0 || sock_recv_len != event_context_len) {
885 ERR("Failed to receive event context in command payload");
886 *sock_error = 1;
887 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
888 goto end;
889 }
890
891 /* Deserialize event. */
892 {
893 ssize_t len;
894 struct lttng_payload_view event_context_view =
895 lttng_payload_view_from_payload(&event_context_payload, 0, -1);
896
897 len = lttng_event_context_create_from_payload(&event_context_view, &context);
898
899 if (len < 0) {
900 ERR("Failed to create a event context from the received buffer");
901 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
902 goto end;
903 }
904
905 if (len != event_context_len) {
906 ERR("Event context from the received buffer is not the advertised length: expected length = %zu, payload length = %zd",
907 event_context_len,
908 len);
909 ret_code = LTTNG_ERR_INVALID_PROTOCOL;
910 goto end;
911 }
912 }
913
914 *out_event_context = context;
915 context = nullptr;
916 ret_code = LTTNG_OK;
917
918 end:
919 lttng_event_context_destroy(context);
920 lttng_payload_reset(&event_context_payload);
921 return ret_code;
922 }
923
924 /*
925 * Version of setup_lttng_msg() without command header.
926 */
927 static int
928 setup_lttng_msg_no_cmd_header(struct command_ctx *cmd_ctx, void *payload_buf, size_t payload_len)
929 {
930 return setup_lttng_msg(cmd_ctx, payload_buf, payload_len, nullptr, 0);
931 }
932
933 /*
934 * Check if the current kernel tracer supports the session rotation feature.
935 * Return 1 if it does, 0 otherwise.
936 */
937 static int check_rotate_compatible()
938 {
939 int ret = 1;
940
941 if (the_kernel_tracer_version.major != 2 || the_kernel_tracer_version.minor < 11) {
942 DBG("Kernel tracer version is not compatible with the rotation feature");
943 ret = 0;
944 }
945
946 return ret;
947 }
948
949 /*
950 * Send data on a unix socket using the liblttsessiondcomm API.
951 *
952 * Return lttcomm error code.
953 */
954 static int send_unix_sock(int sock, struct lttng_payload_view *view)
955 {
956 int ret;
957 const int fd_count = lttng_payload_view_get_fd_handle_count(view);
958
959 /* Check valid length */
960 if (view->buffer.size == 0) {
961 ret = -1;
962 goto end;
963 }
964
965 ret = lttcomm_send_unix_sock(sock, view->buffer.data, view->buffer.size);
966 if (ret < 0) {
967 goto end;
968 }
969
970 if (fd_count > 0) {
971 ret = lttcomm_send_payload_view_fds_unix_sock(sock, view);
972 if (ret < 0) {
973 goto end;
974 }
975 }
976
977 end:
978 return ret;
979 }
980
981 static void command_ctx_set_status_code(command_ctx& cmd_ctx, enum lttng_error_code status_code)
982 {
983 LTTNG_ASSERT(cmd_ctx.reply_payload.buffer.size >= sizeof(lttcomm_lttng_msg));
984 ((struct lttcomm_lttng_msg *) (cmd_ctx.reply_payload.buffer.data))->ret_code = status_code;
985 }
986
987 /*
988 * Process the command requested by the lttng client within the command
989 * context structure. This function make sure that the return structure (llm)
990 * is set and ready for transmission before returning.
991 *
992 * Return any error encountered or 0 for success.
993 *
994 * "sock" is only used for special-case var. len data.
995 * A command may assume the ownership of the socket, in which case its value
996 * should be set to -1.
997 */
998 static int process_client_msg(struct command_ctx *cmd_ctx, int *sock, int *sock_error)
999 {
1000 int ret = LTTNG_OK;
1001 bool need_tracing_session = true;
1002 bool need_domain;
1003 bool need_consumerd;
1004
1005 if (!lttcomm_sessiond_command_is_valid((lttcomm_sessiond_command) cmd_ctx->lsm.cmd_type)) {
1006 ERR("Unknown client command received: command id = %" PRIu32,
1007 cmd_ctx->lsm.cmd_type);
1008 ret = LTTNG_ERR_UND;
1009 goto error;
1010 }
1011
1012 DBG("Processing client command '%s\' (%d)",
1013 lttcomm_sessiond_command_str((lttcomm_sessiond_command) cmd_ctx->lsm.cmd_type),
1014 cmd_ctx->lsm.cmd_type);
1015
1016 *sock_error = 0;
1017
1018 switch (cmd_ctx->lsm.cmd_type) {
1019 case LTTCOMM_SESSIOND_COMMAND_CREATE_SESSION_EXT:
1020 case LTTCOMM_SESSIOND_COMMAND_DESTROY_SESSION:
1021 case LTTCOMM_SESSIOND_COMMAND_LIST_SESSIONS:
1022 case LTTCOMM_SESSIOND_COMMAND_LIST_DOMAINS:
1023 case LTTCOMM_SESSIOND_COMMAND_START_TRACE:
1024 case LTTCOMM_SESSIOND_COMMAND_STOP_TRACE:
1025 case LTTCOMM_SESSIOND_COMMAND_DATA_PENDING:
1026 case LTTCOMM_SESSIOND_COMMAND_SNAPSHOT_ADD_OUTPUT:
1027 case LTTCOMM_SESSIOND_COMMAND_SNAPSHOT_DEL_OUTPUT:
1028 case LTTCOMM_SESSIOND_COMMAND_SNAPSHOT_LIST_OUTPUT:
1029 case LTTCOMM_SESSIOND_COMMAND_SNAPSHOT_RECORD:
1030 case LTTCOMM_SESSIOND_COMMAND_SAVE_SESSION:
1031 case LTTCOMM_SESSIOND_COMMAND_SET_SESSION_SHM_PATH:
1032 case LTTCOMM_SESSIOND_COMMAND_REGENERATE_METADATA:
1033 case LTTCOMM_SESSIOND_COMMAND_REGENERATE_STATEDUMP:
1034 case LTTCOMM_SESSIOND_COMMAND_ROTATE_SESSION:
1035 case LTTCOMM_SESSIOND_COMMAND_ROTATION_GET_INFO:
1036 case LTTCOMM_SESSIOND_COMMAND_ROTATION_SET_SCHEDULE:
1037 case LTTCOMM_SESSIOND_COMMAND_SESSION_LIST_ROTATION_SCHEDULES:
1038 case LTTCOMM_SESSIOND_COMMAND_CLEAR_SESSION:
1039 case LTTCOMM_SESSIOND_COMMAND_LIST_TRIGGERS:
1040 case LTTCOMM_SESSIOND_COMMAND_EXECUTE_ERROR_QUERY:
1041 case LTTCOMM_SESSIOND_COMMAND_KERNEL_TRACER_STATUS:
1042 need_domain = false;
1043 break;
1044 default:
1045 need_domain = true;
1046 }
1047
1048 /* Needs a functioning consumerd? */
1049 switch (cmd_ctx->lsm.cmd_type) {
1050 case LTTCOMM_SESSIOND_COMMAND_REGISTER_TRIGGER:
1051 case LTTCOMM_SESSIOND_COMMAND_UNREGISTER_TRIGGER:
1052 case LTTCOMM_SESSIOND_COMMAND_EXECUTE_ERROR_QUERY:
1053 need_consumerd = false;
1054 break;
1055 default:
1056 need_consumerd = true;
1057 break;
1058 }
1059
1060 if (the_config.no_kernel && need_domain &&
1061 cmd_ctx->lsm.domain.type == LTTNG_DOMAIN_KERNEL) {
1062 if (!is_root) {
1063 ret = LTTNG_ERR_NEED_ROOT_SESSIOND;
1064 } else {
1065 ret = LTTNG_ERR_KERN_NA;
1066 }
1067 goto error;
1068 }
1069
1070 /* Deny register consumer if we already have a spawned consumer. */
1071 if (cmd_ctx->lsm.cmd_type == LTTCOMM_SESSIOND_COMMAND_REGISTER_CONSUMER) {
1072 pthread_mutex_lock(&the_kconsumer_data.pid_mutex);
1073 if (the_kconsumer_data.pid > 0) {
1074 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
1075 pthread_mutex_unlock(&the_kconsumer_data.pid_mutex);
1076 goto error;
1077 }
1078 pthread_mutex_unlock(&the_kconsumer_data.pid_mutex);
1079 }
1080
1081 /*
1082 * Check for command that don't needs to allocate a returned payload. We do
1083 * this here so we don't have to make the call for no payload at each
1084 * command.
1085 */
1086 switch (cmd_ctx->lsm.cmd_type) {
1087 case LTTCOMM_SESSIOND_COMMAND_LIST_SESSIONS:
1088 case LTTCOMM_SESSIOND_COMMAND_LIST_TRACEPOINTS:
1089 case LTTCOMM_SESSIOND_COMMAND_LIST_TRACEPOINT_FIELDS:
1090 case LTTCOMM_SESSIOND_COMMAND_LIST_DOMAINS:
1091 case LTTCOMM_SESSIOND_COMMAND_LIST_CHANNELS:
1092 case LTTCOMM_SESSIOND_COMMAND_LIST_EVENTS:
1093 case LTTCOMM_SESSIOND_COMMAND_LIST_SYSCALLS:
1094 case LTTCOMM_SESSIOND_COMMAND_SESSION_LIST_ROTATION_SCHEDULES:
1095 case LTTCOMM_SESSIOND_COMMAND_PROCESS_ATTR_TRACKER_GET_POLICY:
1096 case LTTCOMM_SESSIOND_COMMAND_PROCESS_ATTR_TRACKER_GET_INCLUSION_SET:
1097 case LTTCOMM_SESSIOND_COMMAND_DATA_PENDING:
1098 case LTTCOMM_SESSIOND_COMMAND_ROTATE_SESSION:
1099 case LTTCOMM_SESSIOND_COMMAND_ROTATION_GET_INFO:
1100 case LTTCOMM_SESSIOND_COMMAND_REGISTER_TRIGGER:
1101 case LTTCOMM_SESSIOND_COMMAND_LIST_TRIGGERS:
1102 case LTTCOMM_SESSIOND_COMMAND_EXECUTE_ERROR_QUERY:
1103 break;
1104 default:
1105 /* Setup lttng message with no payload */
1106 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, nullptr, 0);
1107 if (ret < 0) {
1108 /* This label does not try to unlock the session */
1109 goto init_setup_error;
1110 }
1111 }
1112
1113 /* Commands that DO NOT need a session. */
1114 switch (cmd_ctx->lsm.cmd_type) {
1115 case LTTCOMM_SESSIOND_COMMAND_CREATE_SESSION_EXT:
1116 case LTTCOMM_SESSIOND_COMMAND_LIST_SESSIONS:
1117 case LTTCOMM_SESSIOND_COMMAND_LIST_TRACEPOINTS:
1118 case LTTCOMM_SESSIOND_COMMAND_LIST_SYSCALLS:
1119 case LTTCOMM_SESSIOND_COMMAND_LIST_TRACEPOINT_FIELDS:
1120 case LTTCOMM_SESSIOND_COMMAND_SAVE_SESSION:
1121 case LTTCOMM_SESSIOND_COMMAND_REGISTER_TRIGGER:
1122 case LTTCOMM_SESSIOND_COMMAND_UNREGISTER_TRIGGER:
1123 case LTTCOMM_SESSIOND_COMMAND_LIST_TRIGGERS:
1124 case LTTCOMM_SESSIOND_COMMAND_EXECUTE_ERROR_QUERY:
1125 case LTTCOMM_SESSIOND_COMMAND_KERNEL_TRACER_STATUS:
1126 need_tracing_session = false;
1127 break;
1128 default:
1129 if (strnlen(cmd_ctx->lsm.session.name, sizeof(cmd_ctx->lsm.session.name)) ==
1130 sizeof(cmd_ctx->lsm.session.name)) {
1131 LTTNG_THROW_INVALID_ARGUMENT_ERROR(
1132 "Session name received from lttng-ctl client is not null-terminated");
1133 }
1134
1135 DBG("Getting session %s by name", cmd_ctx->lsm.session.name);
1136 /*
1137 * We keep the session list lock across _all_ commands
1138 * for now, because the per-session lock does not
1139 * handle teardown properly.
1140 */
1141 session_lock_list();
1142 cmd_ctx->session = session_find_by_name(cmd_ctx->lsm.session.name);
1143 if (cmd_ctx->session == nullptr) {
1144 ret = LTTNG_ERR_SESS_NOT_FOUND;
1145 goto error;
1146 } else {
1147 /* Acquire lock for the session */
1148 session_lock(cmd_ctx->session);
1149 }
1150 break;
1151 }
1152
1153 /*
1154 * Commands that need a valid session but should NOT create one if none
1155 * exists. Instead of creating one and destroying it when the command is
1156 * handled, process that right before so we save some round trip in useless
1157 * code path.
1158 */
1159 switch (cmd_ctx->lsm.cmd_type) {
1160 case LTTCOMM_SESSIOND_COMMAND_DISABLE_CHANNEL:
1161 case LTTCOMM_SESSIOND_COMMAND_DISABLE_EVENT:
1162 switch (cmd_ctx->lsm.domain.type) {
1163 case LTTNG_DOMAIN_KERNEL:
1164 if (!cmd_ctx->session->kernel_session) {
1165 ret = LTTNG_ERR_NO_CHANNEL;
1166 goto error;
1167 }
1168 break;
1169 case LTTNG_DOMAIN_JUL:
1170 case LTTNG_DOMAIN_LOG4J:
1171 case LTTNG_DOMAIN_PYTHON:
1172 case LTTNG_DOMAIN_UST:
1173 if (!cmd_ctx->session->ust_session) {
1174 ret = LTTNG_ERR_NO_CHANNEL;
1175 goto error;
1176 }
1177 break;
1178 default:
1179 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1180 goto error;
1181 }
1182 default:
1183 break;
1184 }
1185
1186 if (!need_domain) {
1187 goto skip_domain;
1188 }
1189
1190 /*
1191 * Check domain type for specific "pre-action".
1192 */
1193 switch (cmd_ctx->lsm.domain.type) {
1194 case LTTNG_DOMAIN_KERNEL:
1195 if (!is_root) {
1196 ret = LTTNG_ERR_NEED_ROOT_SESSIOND;
1197 goto error;
1198 }
1199
1200 /* Kernel tracer check */
1201 if (!kernel_tracer_is_initialized()) {
1202 /* Basically, load kernel tracer modules */
1203 ret = init_kernel_tracer();
1204 if (ret != 0) {
1205 goto error;
1206 }
1207 }
1208
1209 /* Consumer is in an ERROR state. Report back to client */
1210 if (need_consumerd && uatomic_read(&the_kernel_consumerd_state) == CONSUMER_ERROR) {
1211 ret = LTTNG_ERR_NO_KERNCONSUMERD;
1212 goto error;
1213 }
1214
1215 /* Need a session for kernel command */
1216 if (need_tracing_session) {
1217 if (cmd_ctx->session->kernel_session == nullptr) {
1218 ret = create_kernel_session(cmd_ctx->session);
1219 if (ret != LTTNG_OK) {
1220 ret = LTTNG_ERR_KERN_SESS_FAIL;
1221 goto error;
1222 }
1223 }
1224
1225 /* Start the kernel consumer daemon */
1226 pthread_mutex_lock(&the_kconsumer_data.pid_mutex);
1227 if (the_kconsumer_data.pid == 0 &&
1228 cmd_ctx->lsm.cmd_type != LTTCOMM_SESSIOND_COMMAND_REGISTER_CONSUMER) {
1229 pthread_mutex_unlock(&the_kconsumer_data.pid_mutex);
1230 ret = start_consumerd(&the_kconsumer_data);
1231 if (ret < 0) {
1232 ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
1233 goto error;
1234 }
1235 uatomic_set(&the_kernel_consumerd_state, CONSUMER_STARTED);
1236 } else {
1237 pthread_mutex_unlock(&the_kconsumer_data.pid_mutex);
1238 }
1239
1240 /*
1241 * The consumer was just spawned so we need to add the socket to
1242 * the consumer output of the session if exist.
1243 */
1244 ret = consumer_create_socket(&the_kconsumer_data,
1245 cmd_ctx->session->kernel_session->consumer);
1246 if (ret < 0) {
1247 goto error;
1248 }
1249 }
1250
1251 break;
1252 case LTTNG_DOMAIN_JUL:
1253 case LTTNG_DOMAIN_LOG4J:
1254 case LTTNG_DOMAIN_PYTHON:
1255 if (!agent_tracing_is_enabled()) {
1256 ret = LTTNG_ERR_AGENT_TRACING_DISABLED;
1257 goto error;
1258 }
1259 /* Fallthrough */
1260 case LTTNG_DOMAIN_UST:
1261 {
1262 if (!ust_app_supported()) {
1263 ret = LTTNG_ERR_NO_UST;
1264 goto error;
1265 }
1266
1267 /* Consumer is in an ERROR state. Report back to client */
1268 if (need_consumerd && uatomic_read(&the_ust_consumerd_state) == CONSUMER_ERROR) {
1269 ret = LTTNG_ERR_NO_USTCONSUMERD;
1270 goto error;
1271 }
1272
1273 if (need_tracing_session) {
1274 /* Create UST session if none exist. */
1275 if (cmd_ctx->session->ust_session == nullptr) {
1276 lttng_domain domain = cmd_ctx->lsm.domain;
1277 ret = create_ust_session(cmd_ctx->session, &domain);
1278 if (ret != LTTNG_OK) {
1279 goto error;
1280 }
1281 }
1282
1283 /* Start the UST consumer daemons */
1284 /* 64-bit */
1285 pthread_mutex_lock(&the_ustconsumer64_data.pid_mutex);
1286 if (the_config.consumerd64_bin_path.value &&
1287 the_ustconsumer64_data.pid == 0 &&
1288 cmd_ctx->lsm.cmd_type != LTTCOMM_SESSIOND_COMMAND_REGISTER_CONSUMER) {
1289 pthread_mutex_unlock(&the_ustconsumer64_data.pid_mutex);
1290 ret = start_consumerd(&the_ustconsumer64_data);
1291 if (ret < 0) {
1292 ret = LTTNG_ERR_UST_CONSUMER64_FAIL;
1293 uatomic_set(&the_ust_consumerd64_fd, -EINVAL);
1294 goto error;
1295 }
1296
1297 uatomic_set(&the_ust_consumerd64_fd,
1298 the_ustconsumer64_data.cmd_sock);
1299 uatomic_set(&the_ust_consumerd_state, CONSUMER_STARTED);
1300 } else {
1301 pthread_mutex_unlock(&the_ustconsumer64_data.pid_mutex);
1302 }
1303
1304 /*
1305 * Setup socket for consumer 64 bit. No need for atomic access
1306 * since it was set above and can ONLY be set in this thread.
1307 */
1308 ret = consumer_create_socket(&the_ustconsumer64_data,
1309 cmd_ctx->session->ust_session->consumer);
1310 if (ret < 0) {
1311 goto error;
1312 }
1313
1314 /* 32-bit */
1315 pthread_mutex_lock(&the_ustconsumer32_data.pid_mutex);
1316 if (the_config.consumerd32_bin_path.value &&
1317 the_ustconsumer32_data.pid == 0 &&
1318 cmd_ctx->lsm.cmd_type != LTTCOMM_SESSIOND_COMMAND_REGISTER_CONSUMER) {
1319 pthread_mutex_unlock(&the_ustconsumer32_data.pid_mutex);
1320 ret = start_consumerd(&the_ustconsumer32_data);
1321 if (ret < 0) {
1322 ret = LTTNG_ERR_UST_CONSUMER32_FAIL;
1323 uatomic_set(&the_ust_consumerd32_fd, -EINVAL);
1324 goto error;
1325 }
1326
1327 uatomic_set(&the_ust_consumerd32_fd,
1328 the_ustconsumer32_data.cmd_sock);
1329 uatomic_set(&the_ust_consumerd_state, CONSUMER_STARTED);
1330 } else {
1331 pthread_mutex_unlock(&the_ustconsumer32_data.pid_mutex);
1332 }
1333
1334 /*
1335 * Setup socket for consumer 32 bit. No need for atomic access
1336 * since it was set above and can ONLY be set in this thread.
1337 */
1338 ret = consumer_create_socket(&the_ustconsumer32_data,
1339 cmd_ctx->session->ust_session->consumer);
1340 if (ret < 0) {
1341 goto error;
1342 }
1343 }
1344 break;
1345 }
1346 default:
1347 break;
1348 }
1349 skip_domain:
1350
1351 /* Validate consumer daemon state when start/stop trace command */
1352 if (cmd_ctx->lsm.cmd_type == LTTCOMM_SESSIOND_COMMAND_START_TRACE ||
1353 cmd_ctx->lsm.cmd_type == LTTCOMM_SESSIOND_COMMAND_STOP_TRACE) {
1354 switch (cmd_ctx->lsm.domain.type) {
1355 case LTTNG_DOMAIN_NONE:
1356 break;
1357 case LTTNG_DOMAIN_JUL:
1358 case LTTNG_DOMAIN_LOG4J:
1359 case LTTNG_DOMAIN_PYTHON:
1360 case LTTNG_DOMAIN_UST:
1361 if (uatomic_read(&the_ust_consumerd_state) != CONSUMER_STARTED) {
1362 ret = LTTNG_ERR_NO_USTCONSUMERD;
1363 goto error;
1364 }
1365 break;
1366 case LTTNG_DOMAIN_KERNEL:
1367 if (uatomic_read(&the_kernel_consumerd_state) != CONSUMER_STARTED) {
1368 ret = LTTNG_ERR_NO_KERNCONSUMERD;
1369 goto error;
1370 }
1371 break;
1372 default:
1373 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
1374 goto error;
1375 }
1376 }
1377
1378 /*
1379 * Check that the UID matches that of the tracing session.
1380 * The root user can interact with all sessions.
1381 */
1382 if (need_tracing_session) {
1383 if (!session_access_ok(cmd_ctx->session,
1384 LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds)) ||
1385 cmd_ctx->session->destroyed) {
1386 ret = LTTNG_ERR_EPERM;
1387 goto error;
1388 }
1389 }
1390
1391 /*
1392 * Send relayd information to consumer as soon as we have a domain and a
1393 * session defined.
1394 */
1395 if (cmd_ctx->session && need_domain) {
1396 /*
1397 * Setup relayd if not done yet. If the relayd information was already
1398 * sent to the consumer, this call will gracefully return.
1399 */
1400 ret = cmd_setup_relayd(cmd_ctx->session);
1401 if (ret != LTTNG_OK) {
1402 goto error;
1403 }
1404 }
1405
1406 /* Process by command type */
1407 switch (cmd_ctx->lsm.cmd_type) {
1408 case LTTCOMM_SESSIOND_COMMAND_ADD_CONTEXT:
1409 {
1410 struct lttng_event_context *event_context = nullptr;
1411 const enum lttng_error_code ret_code =
1412 receive_lttng_event_context(cmd_ctx, *sock, sock_error, &event_context);
1413
1414 if (ret_code != LTTNG_OK) {
1415 ret = (int) ret_code;
1416 goto error;
1417 }
1418
1419 ret = cmd_add_context(cmd_ctx, event_context, the_kernel_poll_pipe[1]);
1420 lttng_event_context_destroy(event_context);
1421 break;
1422 }
1423 case LTTCOMM_SESSIOND_COMMAND_DISABLE_CHANNEL:
1424 {
1425 ret = cmd_disable_channel(cmd_ctx->session,
1426 cmd_ctx->lsm.domain.type,
1427 cmd_ctx->lsm.u.disable.channel_name);
1428 break;
1429 }
1430 case LTTCOMM_SESSIOND_COMMAND_ENABLE_CHANNEL:
1431 {
1432 ret = cmd_enable_channel(cmd_ctx, *sock, the_kernel_poll_pipe[1]);
1433 break;
1434 }
1435 case LTTCOMM_SESSIOND_COMMAND_PROCESS_ATTR_TRACKER_ADD_INCLUDE_VALUE:
1436 case LTTCOMM_SESSIOND_COMMAND_PROCESS_ATTR_TRACKER_REMOVE_INCLUDE_VALUE:
1437 {
1438 struct lttng_dynamic_buffer payload;
1439 struct lttng_buffer_view payload_view;
1440 const bool add_value = cmd_ctx->lsm.cmd_type ==
1441 LTTCOMM_SESSIOND_COMMAND_PROCESS_ATTR_TRACKER_ADD_INCLUDE_VALUE;
1442 const size_t name_len =
1443 cmd_ctx->lsm.u.process_attr_tracker_add_remove_include_value.name_len;
1444 const enum lttng_domain_type domain_type =
1445 (enum lttng_domain_type) cmd_ctx->lsm.domain.type;
1446 const enum lttng_process_attr process_attr =
1447 (enum lttng_process_attr) cmd_ctx->lsm.u
1448 .process_attr_tracker_add_remove_include_value.process_attr;
1449 const enum lttng_process_attr_value_type value_type =
1450 (enum lttng_process_attr_value_type) cmd_ctx->lsm.u
1451 .process_attr_tracker_add_remove_include_value.value_type;
1452 struct process_attr_value *value;
1453 enum lttng_error_code ret_code;
1454 long login_name_max;
1455
1456 login_name_max = sysconf(_SC_LOGIN_NAME_MAX);
1457 if (login_name_max < 0) {
1458 PERROR("Failed to get _SC_LOGIN_NAME_MAX system configuration");
1459 ret = LTTNG_ERR_INVALID;
1460 goto error;
1461 }
1462
1463 /* Receive remaining variable length payload if applicable. */
1464 if (name_len > login_name_max) {
1465 /*
1466 * POSIX mandates user and group names that are at least
1467 * 8 characters long. Note that although shadow-utils
1468 * (useradd, groupaadd, etc.) use 32 chars as their
1469 * limit (from bits/utmp.h, UT_NAMESIZE),
1470 * LOGIN_NAME_MAX is defined to 256.
1471 */
1472 ERR("Rejecting process attribute tracker value %s as the provided exceeds the maximal allowed length: argument length = %zu, maximal length = %ld",
1473 add_value ? "addition" : "removal",
1474 name_len,
1475 login_name_max);
1476 ret = LTTNG_ERR_INVALID;
1477 goto error;
1478 }
1479
1480 lttng_dynamic_buffer_init(&payload);
1481 if (name_len != 0) {
1482 /*
1483 * Receive variable payload for user/group name
1484 * arguments.
1485 */
1486 ret = lttng_dynamic_buffer_set_size(&payload, name_len);
1487 if (ret) {
1488 ERR("Failed to allocate buffer to receive payload of %s process attribute tracker value argument",
1489 add_value ? "add" : "remove");
1490 ret = LTTNG_ERR_NOMEM;
1491 goto error_add_remove_tracker_value;
1492 }
1493
1494 ret = lttcomm_recv_unix_sock(*sock, payload.data, name_len);
1495 if (ret <= 0) {
1496 ERR("Failed to receive payload of %s process attribute tracker value argument",
1497 add_value ? "add" : "remove");
1498 *sock_error = 1;
1499 ret = LTTNG_ERR_INVALID_PROTOCOL;
1500 goto error_add_remove_tracker_value;
1501 }
1502 }
1503
1504 payload_view = lttng_buffer_view_from_dynamic_buffer(&payload, 0, name_len);
1505 if (name_len > 0 && !lttng_buffer_view_is_valid(&payload_view)) {
1506 ret = LTTNG_ERR_INVALID_PROTOCOL;
1507 goto error_add_remove_tracker_value;
1508 }
1509
1510 /*
1511 * Validate the value type and domains are legal for the process
1512 * attribute tracker that is specified and convert the value to
1513 * add/remove to the internal sessiond representation.
1514 */
1515 ret_code = process_attr_value_from_comm(
1516 domain_type,
1517 process_attr,
1518 value_type,
1519 &cmd_ctx->lsm.u.process_attr_tracker_add_remove_include_value.integral_value,
1520 &payload_view,
1521 &value);
1522 if (ret_code != LTTNG_OK) {
1523 ret = ret_code;
1524 goto error_add_remove_tracker_value;
1525 }
1526
1527 if (add_value) {
1528 ret = cmd_process_attr_tracker_inclusion_set_add_value(
1529 cmd_ctx->session, domain_type, process_attr, value);
1530 } else {
1531 ret = cmd_process_attr_tracker_inclusion_set_remove_value(
1532 cmd_ctx->session, domain_type, process_attr, value);
1533 }
1534 process_attr_value_destroy(value);
1535 error_add_remove_tracker_value:
1536 lttng_dynamic_buffer_reset(&payload);
1537 break;
1538 }
1539 case LTTCOMM_SESSIOND_COMMAND_PROCESS_ATTR_TRACKER_GET_POLICY:
1540 {
1541 enum lttng_tracking_policy tracking_policy;
1542 const enum lttng_domain_type domain_type =
1543 (enum lttng_domain_type) cmd_ctx->lsm.domain.type;
1544 const enum lttng_process_attr process_attr =
1545 (enum lttng_process_attr) cmd_ctx->lsm.u
1546 .process_attr_tracker_get_tracking_policy.process_attr;
1547
1548 ret = cmd_process_attr_tracker_get_tracking_policy(
1549 cmd_ctx->session, domain_type, process_attr, &tracking_policy);
1550 if (ret != LTTNG_OK) {
1551 goto error;
1552 }
1553
1554 uint32_t tracking_policy_u32 = tracking_policy;
1555 ret = setup_lttng_msg_no_cmd_header(
1556 cmd_ctx, &tracking_policy_u32, sizeof(uint32_t));
1557 if (ret < 0) {
1558 ret = LTTNG_ERR_NOMEM;
1559 goto error;
1560 }
1561 ret = LTTNG_OK;
1562 break;
1563 }
1564 case LTTCOMM_SESSIOND_COMMAND_PROCESS_ATTR_TRACKER_SET_POLICY:
1565 {
1566 const enum lttng_tracking_policy tracking_policy =
1567 (enum lttng_tracking_policy) cmd_ctx->lsm.u
1568 .process_attr_tracker_set_tracking_policy.tracking_policy;
1569 const enum lttng_domain_type domain_type =
1570 (enum lttng_domain_type) cmd_ctx->lsm.domain.type;
1571 const enum lttng_process_attr process_attr =
1572 (enum lttng_process_attr) cmd_ctx->lsm.u
1573 .process_attr_tracker_set_tracking_policy.process_attr;
1574
1575 ret = cmd_process_attr_tracker_set_tracking_policy(
1576 cmd_ctx->session, domain_type, process_attr, tracking_policy);
1577 if (ret != LTTNG_OK) {
1578 goto error;
1579 }
1580 break;
1581 }
1582 case LTTCOMM_SESSIOND_COMMAND_PROCESS_ATTR_TRACKER_GET_INCLUSION_SET:
1583 {
1584 struct lttng_process_attr_values *values;
1585 struct lttng_dynamic_buffer reply;
1586 const enum lttng_domain_type domain_type =
1587 (enum lttng_domain_type) cmd_ctx->lsm.domain.type;
1588 const enum lttng_process_attr process_attr =
1589 (enum lttng_process_attr)
1590 cmd_ctx->lsm.u.process_attr_tracker_get_inclusion_set.process_attr;
1591
1592 ret = cmd_process_attr_tracker_get_inclusion_set(
1593 cmd_ctx->session, domain_type, process_attr, &values);
1594 if (ret != LTTNG_OK) {
1595 goto error;
1596 }
1597
1598 lttng_dynamic_buffer_init(&reply);
1599 ret = lttng_process_attr_values_serialize(values, &reply);
1600 if (ret < 0) {
1601 goto error_tracker_get_inclusion_set;
1602 }
1603
1604 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, reply.data, reply.size);
1605 if (ret < 0) {
1606 ret = LTTNG_ERR_NOMEM;
1607 goto error_tracker_get_inclusion_set;
1608 }
1609 ret = LTTNG_OK;
1610
1611 error_tracker_get_inclusion_set:
1612 lttng_process_attr_values_destroy(values);
1613 lttng_dynamic_buffer_reset(&reply);
1614 break;
1615 }
1616 case LTTCOMM_SESSIOND_COMMAND_ENABLE_EVENT:
1617 case LTTCOMM_SESSIOND_COMMAND_DISABLE_EVENT:
1618 {
1619 struct lttng_event *event;
1620 char *filter_expression;
1621 struct lttng_event_exclusion *exclusions;
1622 struct lttng_bytecode *bytecode;
1623 const enum lttng_error_code ret_code = receive_lttng_event(cmd_ctx,
1624 *sock,
1625 sock_error,
1626 &event,
1627 &filter_expression,
1628 &bytecode,
1629 &exclusions);
1630
1631 if (ret_code != LTTNG_OK) {
1632 ret = (int) ret_code;
1633 goto error;
1634 }
1635
1636 /*
1637 * Ownership of filter_expression, exclusions, and bytecode is
1638 * always transferred.
1639 */
1640 ret = cmd_ctx->lsm.cmd_type == LTTCOMM_SESSIOND_COMMAND_ENABLE_EVENT ?
1641 cmd_enable_event(cmd_ctx,
1642 event,
1643 filter_expression,
1644 exclusions,
1645 bytecode,
1646 the_kernel_poll_pipe[1]) :
1647 cmd_disable_event(cmd_ctx, event, filter_expression, bytecode, exclusions);
1648 lttng_event_destroy(event);
1649 break;
1650 }
1651 case LTTCOMM_SESSIOND_COMMAND_LIST_TRACEPOINTS:
1652 {
1653 enum lttng_error_code ret_code;
1654 size_t original_payload_size;
1655 size_t payload_size;
1656 const size_t command_header_size = sizeof(struct lttcomm_list_command_header);
1657
1658 ret = setup_empty_lttng_msg(cmd_ctx);
1659 if (ret) {
1660 ret = LTTNG_ERR_NOMEM;
1661 goto setup_error;
1662 }
1663
1664 original_payload_size = cmd_ctx->reply_payload.buffer.size;
1665
1666 session_lock_list();
1667 ret_code = cmd_list_tracepoints(cmd_ctx->lsm.domain.type, &cmd_ctx->reply_payload);
1668 session_unlock_list();
1669 if (ret_code != LTTNG_OK) {
1670 ret = (int) ret_code;
1671 goto error;
1672 }
1673
1674 payload_size = cmd_ctx->reply_payload.buffer.size - command_header_size -
1675 original_payload_size;
1676 update_lttng_msg(cmd_ctx, command_header_size, payload_size);
1677
1678 ret = LTTNG_OK;
1679 break;
1680 }
1681 case LTTCOMM_SESSIOND_COMMAND_LIST_TRACEPOINT_FIELDS:
1682 {
1683 enum lttng_error_code ret_code;
1684 size_t original_payload_size;
1685 size_t payload_size;
1686 const size_t command_header_size = sizeof(struct lttcomm_list_command_header);
1687
1688 ret = setup_empty_lttng_msg(cmd_ctx);
1689 if (ret) {
1690 ret = LTTNG_ERR_NOMEM;
1691 goto setup_error;
1692 }
1693
1694 original_payload_size = cmd_ctx->reply_payload.buffer.size;
1695
1696 session_lock_list();
1697 ret_code = cmd_list_tracepoint_fields(cmd_ctx->lsm.domain.type,
1698 &cmd_ctx->reply_payload);
1699 session_unlock_list();
1700 if (ret_code != LTTNG_OK) {
1701 ret = (int) ret_code;
1702 goto error;
1703 }
1704
1705 payload_size = cmd_ctx->reply_payload.buffer.size - command_header_size -
1706 original_payload_size;
1707 update_lttng_msg(cmd_ctx, command_header_size, payload_size);
1708
1709 ret = LTTNG_OK;
1710 break;
1711 }
1712 case LTTCOMM_SESSIOND_COMMAND_LIST_SYSCALLS:
1713 {
1714 enum lttng_error_code ret_code;
1715 size_t original_payload_size;
1716 size_t payload_size;
1717 const size_t command_header_size = sizeof(struct lttcomm_list_command_header);
1718
1719 ret = setup_empty_lttng_msg(cmd_ctx);
1720 if (ret) {
1721 ret = LTTNG_ERR_NOMEM;
1722 goto setup_error;
1723 }
1724
1725 original_payload_size = cmd_ctx->reply_payload.buffer.size;
1726
1727 ret_code = cmd_list_syscalls(&cmd_ctx->reply_payload);
1728 if (ret_code != LTTNG_OK) {
1729 ret = (int) ret_code;
1730 goto error;
1731 }
1732
1733 payload_size = cmd_ctx->reply_payload.buffer.size - command_header_size -
1734 original_payload_size;
1735 update_lttng_msg(cmd_ctx, command_header_size, payload_size);
1736
1737 ret = LTTNG_OK;
1738 break;
1739 }
1740 case LTTCOMM_SESSIOND_COMMAND_SET_CONSUMER_URI:
1741 {
1742 size_t nb_uri, len;
1743 struct lttng_uri *uris;
1744
1745 nb_uri = cmd_ctx->lsm.u.uri.size;
1746 len = nb_uri * sizeof(struct lttng_uri);
1747
1748 if (nb_uri == 0) {
1749 ret = LTTNG_ERR_INVALID;
1750 goto error;
1751 }
1752
1753 uris = calloc<lttng_uri>(nb_uri);
1754 if (uris == nullptr) {
1755 ret = LTTNG_ERR_FATAL;
1756 goto error;
1757 }
1758
1759 /* Receive variable len data */
1760 DBG("Receiving %zu URI(s) from client ...", nb_uri);
1761 ret = lttcomm_recv_unix_sock(*sock, uris, len);
1762 if (ret <= 0) {
1763 DBG("No URIs received from client... continuing");
1764 *sock_error = 1;
1765 ret = LTTNG_ERR_SESSION_FAIL;
1766 free(uris);
1767 goto error;
1768 }
1769
1770 ret = cmd_set_consumer_uri(cmd_ctx->session, nb_uri, uris);
1771 free(uris);
1772 if (ret != LTTNG_OK) {
1773 goto error;
1774 }
1775
1776 break;
1777 }
1778 case LTTCOMM_SESSIOND_COMMAND_START_TRACE:
1779 {
1780 /*
1781 * On the first start, if we have a kernel session and we have
1782 * enabled time or size-based rotations, we have to make sure
1783 * the kernel tracer supports it.
1784 */
1785 if (!cmd_ctx->session->has_been_started && cmd_ctx->session->kernel_session &&
1786 (cmd_ctx->session->rotate_timer_period || cmd_ctx->session->rotate_size) &&
1787 !check_rotate_compatible()) {
1788 DBG("Kernel tracer version is not compatible with the rotation feature");
1789 ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
1790 goto error;
1791 }
1792 ret = cmd_start_trace(cmd_ctx->session);
1793 break;
1794 }
1795 case LTTCOMM_SESSIOND_COMMAND_STOP_TRACE:
1796 {
1797 ret = cmd_stop_trace(cmd_ctx->session);
1798 break;
1799 }
1800 case LTTCOMM_SESSIOND_COMMAND_DESTROY_SESSION:
1801 {
1802 ret = cmd_destroy_session(cmd_ctx->session, sock);
1803 break;
1804 }
1805 case LTTCOMM_SESSIOND_COMMAND_LIST_DOMAINS:
1806 {
1807 ssize_t nb_dom;
1808 struct lttng_domain *domains = nullptr;
1809
1810 nb_dom = cmd_list_domains(cmd_ctx->session, &domains);
1811 if (nb_dom < 0) {
1812 /* Return value is a negative lttng_error_code. */
1813 ret = -nb_dom;
1814 goto error;
1815 }
1816
1817 ret = setup_lttng_msg_no_cmd_header(
1818 cmd_ctx, domains, nb_dom * sizeof(struct lttng_domain));
1819 free(domains);
1820
1821 if (ret < 0) {
1822 goto setup_error;
1823 }
1824
1825 ret = LTTNG_OK;
1826 break;
1827 }
1828 case LTTCOMM_SESSIOND_COMMAND_LIST_CHANNELS:
1829 {
1830 enum lttng_error_code ret_code;
1831 size_t original_payload_size;
1832 size_t payload_size;
1833 const size_t command_header_size = sizeof(struct lttcomm_list_command_header);
1834
1835 ret = setup_empty_lttng_msg(cmd_ctx);
1836 if (ret) {
1837 ret = LTTNG_ERR_NOMEM;
1838 goto setup_error;
1839 }
1840
1841 original_payload_size = cmd_ctx->reply_payload.buffer.size;
1842
1843 ret_code = cmd_list_channels(
1844 cmd_ctx->lsm.domain.type, cmd_ctx->session, &cmd_ctx->reply_payload);
1845 if (ret_code != LTTNG_OK) {
1846 ret = (int) ret_code;
1847 goto error;
1848 }
1849
1850 payload_size = cmd_ctx->reply_payload.buffer.size - command_header_size -
1851 original_payload_size;
1852 update_lttng_msg(cmd_ctx, command_header_size, payload_size);
1853
1854 ret = LTTNG_OK;
1855 break;
1856 }
1857 case LTTCOMM_SESSIOND_COMMAND_LIST_EVENTS:
1858 {
1859 enum lttng_error_code ret_code;
1860 size_t original_payload_size;
1861 size_t payload_size;
1862 const size_t command_header_size = sizeof(struct lttcomm_list_command_header);
1863
1864 ret = setup_empty_lttng_msg(cmd_ctx);
1865 if (ret) {
1866 ret = LTTNG_ERR_NOMEM;
1867 goto setup_error;
1868 }
1869
1870 original_payload_size = cmd_ctx->reply_payload.buffer.size;
1871
1872 ret_code = cmd_list_events(cmd_ctx->lsm.domain.type,
1873 cmd_ctx->session,
1874 cmd_ctx->lsm.u.list.channel_name,
1875 &cmd_ctx->reply_payload);
1876 if (ret_code != LTTNG_OK) {
1877 ret = (int) ret_code;
1878 goto error;
1879 }
1880
1881 payload_size = cmd_ctx->reply_payload.buffer.size - command_header_size -
1882 original_payload_size;
1883 update_lttng_msg(cmd_ctx, command_header_size, payload_size);
1884
1885 ret = LTTNG_OK;
1886 break;
1887 }
1888 case LTTCOMM_SESSIOND_COMMAND_LIST_SESSIONS:
1889 {
1890 unsigned int nr_sessions;
1891 lttng_session *sessions_payload = nullptr;
1892 size_t payload_len = 0;
1893
1894 session_lock_list();
1895 nr_sessions = lttng_sessions_count(LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
1896 LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds));
1897
1898 if (nr_sessions > 0) {
1899 payload_len = (sizeof(struct lttng_session) * nr_sessions) +
1900 (sizeof(struct lttng_session_extended) * nr_sessions);
1901 sessions_payload = zmalloc<lttng_session>(payload_len);
1902 if (!sessions_payload) {
1903 session_unlock_list();
1904 ret = -ENOMEM;
1905 goto setup_error;
1906 }
1907
1908 cmd_list_lttng_sessions(sessions_payload,
1909 nr_sessions,
1910 LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
1911 LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds));
1912 }
1913
1914 session_unlock_list();
1915
1916 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, sessions_payload, payload_len);
1917 free(sessions_payload);
1918
1919 if (ret < 0) {
1920 goto setup_error;
1921 }
1922
1923 ret = LTTNG_OK;
1924 break;
1925 }
1926 case LTTCOMM_SESSIOND_COMMAND_REGISTER_CONSUMER:
1927 {
1928 struct consumer_data *cdata;
1929
1930 switch (cmd_ctx->lsm.domain.type) {
1931 case LTTNG_DOMAIN_KERNEL:
1932 cdata = &the_kconsumer_data;
1933 break;
1934 default:
1935 ret = LTTNG_ERR_UND;
1936 goto error;
1937 }
1938
1939 ret = cmd_register_consumer(
1940 cmd_ctx->session, cmd_ctx->lsm.domain.type, cmd_ctx->lsm.u.reg.path, cdata);
1941 break;
1942 }
1943 case LTTCOMM_SESSIOND_COMMAND_KERNEL_TRACER_STATUS:
1944 {
1945 uint32_t u_status;
1946 enum lttng_kernel_tracer_status status;
1947
1948 ret = cmd_kernel_tracer_status(&status);
1949 if (ret != LTTNG_OK) {
1950 goto error;
1951 }
1952
1953 u_status = (uint32_t) status;
1954 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &u_status, 4);
1955 if (ret < 0) {
1956 goto error;
1957 }
1958
1959 ret = LTTNG_OK;
1960 break;
1961 }
1962 case LTTCOMM_SESSIOND_COMMAND_DATA_PENDING:
1963 {
1964 int pending_ret;
1965 uint8_t pending_ret_byte;
1966
1967 pending_ret = cmd_data_pending(cmd_ctx->session);
1968
1969 /*
1970 * FIXME
1971 *
1972 * This function may returns 0 or 1 to indicate whether or not
1973 * there is data pending. In case of error, it should return an
1974 * LTTNG_ERR code. However, some code paths may still return
1975 * a nondescript error code, which we handle by returning an
1976 * "unknown" error.
1977 */
1978 if (pending_ret == 0 || pending_ret == 1) {
1979 /*
1980 * ret will be set to LTTNG_OK at the end of
1981 * this function.
1982 */
1983 } else if (pending_ret <= LTTNG_OK || pending_ret >= LTTNG_ERR_NR) {
1984 ret = LTTNG_ERR_UNK;
1985 goto error;
1986 } else {
1987 ret = pending_ret;
1988 goto error;
1989 }
1990
1991 pending_ret_byte = (uint8_t) pending_ret;
1992
1993 /* 1 byte to return whether or not data is pending */
1994 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &pending_ret_byte, 1);
1995
1996 if (ret < 0) {
1997 goto setup_error;
1998 }
1999
2000 ret = LTTNG_OK;
2001 break;
2002 }
2003 case LTTCOMM_SESSIOND_COMMAND_SNAPSHOT_ADD_OUTPUT:
2004 {
2005 uint32_t snapshot_id;
2006 struct lttcomm_lttng_output_id reply;
2007 lttng_snapshot_output output = cmd_ctx->lsm.u.snapshot_output.output;
2008
2009 ret = cmd_snapshot_add_output(cmd_ctx->session, &output, &snapshot_id);
2010 if (ret != LTTNG_OK) {
2011 goto error;
2012 }
2013 reply.id = snapshot_id;
2014
2015 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &reply, sizeof(reply));
2016 if (ret < 0) {
2017 goto setup_error;
2018 }
2019
2020 /* Copy output list into message payload */
2021 ret = LTTNG_OK;
2022 break;
2023 }
2024 case LTTCOMM_SESSIOND_COMMAND_SNAPSHOT_DEL_OUTPUT:
2025 {
2026 lttng_snapshot_output output = cmd_ctx->lsm.u.snapshot_output.output;
2027 ret = cmd_snapshot_del_output(cmd_ctx->session, &output);
2028 break;
2029 }
2030 case LTTCOMM_SESSIOND_COMMAND_SNAPSHOT_LIST_OUTPUT:
2031 {
2032 ssize_t nb_output;
2033 struct lttng_snapshot_output *outputs = nullptr;
2034
2035 nb_output = cmd_snapshot_list_outputs(cmd_ctx->session, &outputs);
2036 if (nb_output < 0) {
2037 ret = -nb_output;
2038 goto error;
2039 }
2040
2041 LTTNG_ASSERT((nb_output > 0 && outputs) || nb_output == 0);
2042 ret = setup_lttng_msg_no_cmd_header(
2043 cmd_ctx, outputs, nb_output * sizeof(struct lttng_snapshot_output));
2044 free(outputs);
2045
2046 if (ret < 0) {
2047 goto setup_error;
2048 }
2049
2050 ret = LTTNG_OK;
2051 break;
2052 }
2053 case LTTCOMM_SESSIOND_COMMAND_SNAPSHOT_RECORD:
2054 {
2055 lttng_snapshot_output output = cmd_ctx->lsm.u.snapshot_record.output;
2056 ret = cmd_snapshot_record(cmd_ctx->session, &output, 0); // RFC: set to zero since
2057 // it's ignored by
2058 // cmd_snapshot_record
2059 break;
2060 }
2061 case LTTCOMM_SESSIOND_COMMAND_CREATE_SESSION_EXT:
2062 {
2063 struct lttng_dynamic_buffer payload;
2064 struct lttng_session_descriptor *return_descriptor = nullptr;
2065
2066 lttng_dynamic_buffer_init(&payload);
2067 ret = cmd_create_session(cmd_ctx, *sock, &return_descriptor);
2068 if (ret != LTTNG_OK) {
2069 goto error;
2070 }
2071
2072 ret = lttng_session_descriptor_serialize(return_descriptor, &payload);
2073 if (ret) {
2074 ERR("Failed to serialize session descriptor in reply to \"create session\" command");
2075 lttng_session_descriptor_destroy(return_descriptor);
2076 ret = LTTNG_ERR_NOMEM;
2077 goto error;
2078 }
2079 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, payload.data, payload.size);
2080 if (ret) {
2081 lttng_session_descriptor_destroy(return_descriptor);
2082 ret = LTTNG_ERR_NOMEM;
2083 goto error;
2084 }
2085 lttng_dynamic_buffer_reset(&payload);
2086 lttng_session_descriptor_destroy(return_descriptor);
2087 ret = LTTNG_OK;
2088 break;
2089 }
2090 case LTTCOMM_SESSIOND_COMMAND_SAVE_SESSION:
2091 {
2092 ret = cmd_save_sessions(&cmd_ctx->lsm.u.save_session.attr, &cmd_ctx->creds);
2093 break;
2094 }
2095 case LTTCOMM_SESSIOND_COMMAND_SET_SESSION_SHM_PATH:
2096 {
2097 ret = cmd_set_session_shm_path(cmd_ctx->session,
2098 cmd_ctx->lsm.u.set_shm_path.shm_path);
2099 break;
2100 }
2101 case LTTCOMM_SESSIOND_COMMAND_REGENERATE_METADATA:
2102 {
2103 ret = cmd_regenerate_metadata(cmd_ctx->session);
2104 break;
2105 }
2106 case LTTCOMM_SESSIOND_COMMAND_REGENERATE_STATEDUMP:
2107 {
2108 ret = cmd_regenerate_statedump(cmd_ctx->session);
2109 break;
2110 }
2111 case LTTCOMM_SESSIOND_COMMAND_REGISTER_TRIGGER:
2112 {
2113 struct lttng_trigger *payload_trigger;
2114 struct lttng_trigger *return_trigger;
2115 size_t original_reply_payload_size;
2116 size_t reply_payload_size;
2117 const struct lttng_credentials cmd_creds = {
2118 .uid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.uid),
2119 .gid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.gid),
2120 };
2121
2122 ret = setup_empty_lttng_msg(cmd_ctx);
2123 if (ret) {
2124 ret = LTTNG_ERR_NOMEM;
2125 goto setup_error;
2126 }
2127
2128 ret = receive_lttng_trigger(cmd_ctx, *sock, sock_error, &payload_trigger);
2129 if (ret != LTTNG_OK) {
2130 goto error;
2131 }
2132
2133 original_reply_payload_size = cmd_ctx->reply_payload.buffer.size;
2134
2135 ret = cmd_register_trigger(&cmd_creds,
2136 payload_trigger,
2137 cmd_ctx->lsm.u.trigger.is_trigger_anonymous,
2138 the_notification_thread_handle,
2139 &return_trigger);
2140 if (ret != LTTNG_OK) {
2141 lttng_trigger_put(payload_trigger);
2142 goto error;
2143 }
2144
2145 ret = lttng_trigger_serialize(return_trigger, &cmd_ctx->reply_payload);
2146 lttng_trigger_put(payload_trigger);
2147 lttng_trigger_put(return_trigger);
2148 if (ret) {
2149 ERR("Failed to serialize trigger in reply to \"register trigger\" command");
2150 ret = LTTNG_ERR_NOMEM;
2151 goto error;
2152 }
2153
2154 reply_payload_size =
2155 cmd_ctx->reply_payload.buffer.size - original_reply_payload_size;
2156
2157 update_lttng_msg(cmd_ctx, 0, reply_payload_size);
2158
2159 ret = LTTNG_OK;
2160 break;
2161 }
2162 case LTTCOMM_SESSIOND_COMMAND_UNREGISTER_TRIGGER:
2163 {
2164 struct lttng_trigger *payload_trigger;
2165 const struct lttng_credentials cmd_creds = {
2166 .uid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.uid),
2167 .gid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.gid),
2168 };
2169
2170 ret = receive_lttng_trigger(cmd_ctx, *sock, sock_error, &payload_trigger);
2171 if (ret != LTTNG_OK) {
2172 goto error;
2173 }
2174
2175 ret = cmd_unregister_trigger(
2176 &cmd_creds, payload_trigger, the_notification_thread_handle);
2177 lttng_trigger_put(payload_trigger);
2178 break;
2179 }
2180 case LTTCOMM_SESSIOND_COMMAND_ROTATE_SESSION:
2181 {
2182 struct lttng_rotate_session_return rotate_return;
2183
2184 DBG("Client rotate session \"%s\"", cmd_ctx->session->name);
2185
2186 memset(&rotate_return, 0, sizeof(rotate_return));
2187 if (cmd_ctx->session->kernel_session && !check_rotate_compatible()) {
2188 DBG("Kernel tracer version is not compatible with the rotation feature");
2189 ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
2190 goto error;
2191 }
2192
2193 ret = cmd_rotate_session(cmd_ctx->session,
2194 &rotate_return,
2195 false,
2196 LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED);
2197 if (ret < 0) {
2198 ret = -ret;
2199 goto error;
2200 }
2201
2202 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &rotate_return, sizeof(rotate_return));
2203 if (ret < 0) {
2204 ret = -ret;
2205 goto error;
2206 }
2207
2208 ret = LTTNG_OK;
2209 break;
2210 }
2211 case LTTCOMM_SESSIOND_COMMAND_ROTATION_GET_INFO:
2212 {
2213 struct lttng_rotation_get_info_return get_info_return;
2214
2215 memset(&get_info_return, 0, sizeof(get_info_return));
2216 ret = cmd_rotate_get_info(cmd_ctx->session,
2217 &get_info_return,
2218 cmd_ctx->lsm.u.get_rotation_info.rotation_id);
2219 if (ret < 0) {
2220 ret = -ret;
2221 goto error;
2222 }
2223
2224 ret = setup_lttng_msg_no_cmd_header(
2225 cmd_ctx, &get_info_return, sizeof(get_info_return));
2226 if (ret < 0) {
2227 ret = -ret;
2228 goto error;
2229 }
2230
2231 ret = LTTNG_OK;
2232 break;
2233 }
2234 case LTTCOMM_SESSIOND_COMMAND_ROTATION_SET_SCHEDULE:
2235 {
2236 bool set_schedule;
2237 enum lttng_rotation_schedule_type schedule_type;
2238 uint64_t value;
2239
2240 if (cmd_ctx->session->kernel_session && !check_rotate_compatible()) {
2241 DBG("Kernel tracer version does not support session rotations");
2242 ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
2243 goto error;
2244 }
2245
2246 set_schedule = cmd_ctx->lsm.u.rotation_set_schedule.set == 1;
2247 schedule_type = (enum lttng_rotation_schedule_type)
2248 cmd_ctx->lsm.u.rotation_set_schedule.type;
2249 value = cmd_ctx->lsm.u.rotation_set_schedule.value;
2250
2251 ret = cmd_rotation_set_schedule(
2252 cmd_ctx->session, set_schedule, schedule_type, value);
2253 if (ret != LTTNG_OK) {
2254 goto error;
2255 }
2256
2257 break;
2258 }
2259 case LTTCOMM_SESSIOND_COMMAND_SESSION_LIST_ROTATION_SCHEDULES:
2260 {
2261 lttng_session_list_schedules_return schedules;
2262
2263 schedules.periodic.set = !!cmd_ctx->session->rotate_timer_period;
2264 schedules.periodic.value = cmd_ctx->session->rotate_timer_period;
2265 schedules.size.set = !!cmd_ctx->session->rotate_size;
2266 schedules.size.value = cmd_ctx->session->rotate_size;
2267
2268 ret = setup_lttng_msg_no_cmd_header(cmd_ctx, &schedules, sizeof(schedules));
2269 if (ret < 0) {
2270 ret = -ret;
2271 goto error;
2272 }
2273
2274 ret = LTTNG_OK;
2275 break;
2276 }
2277 case LTTCOMM_SESSIOND_COMMAND_CLEAR_SESSION:
2278 {
2279 ret = cmd_clear_session(cmd_ctx->session, sock);
2280 break;
2281 }
2282 case LTTCOMM_SESSIOND_COMMAND_LIST_TRIGGERS:
2283 {
2284 struct lttng_triggers *return_triggers = nullptr;
2285 size_t original_payload_size;
2286 size_t payload_size;
2287
2288 ret = setup_empty_lttng_msg(cmd_ctx);
2289 if (ret) {
2290 ret = LTTNG_ERR_NOMEM;
2291 goto setup_error;
2292 }
2293
2294 original_payload_size = cmd_ctx->reply_payload.buffer.size;
2295
2296 ret = cmd_list_triggers(cmd_ctx, the_notification_thread_handle, &return_triggers);
2297 if (ret != LTTNG_OK) {
2298 goto error;
2299 }
2300
2301 LTTNG_ASSERT(return_triggers);
2302 ret = lttng_triggers_serialize(return_triggers, &cmd_ctx->reply_payload);
2303 lttng_triggers_destroy(return_triggers);
2304 if (ret) {
2305 ERR("Failed to serialize triggers in reply to `list triggers` command");
2306 ret = LTTNG_ERR_NOMEM;
2307 goto error;
2308 }
2309
2310 payload_size = cmd_ctx->reply_payload.buffer.size - original_payload_size;
2311
2312 update_lttng_msg(cmd_ctx, 0, payload_size);
2313
2314 ret = LTTNG_OK;
2315 break;
2316 }
2317 case LTTCOMM_SESSIOND_COMMAND_EXECUTE_ERROR_QUERY:
2318 {
2319 struct lttng_error_query *query;
2320 const struct lttng_credentials cmd_creds = {
2321 .uid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.uid),
2322 .gid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.gid),
2323 };
2324 struct lttng_error_query_results *results = nullptr;
2325 size_t original_payload_size;
2326 size_t payload_size;
2327
2328 ret = setup_empty_lttng_msg(cmd_ctx);
2329 if (ret) {
2330 ret = LTTNG_ERR_NOMEM;
2331 goto setup_error;
2332 }
2333
2334 original_payload_size = cmd_ctx->reply_payload.buffer.size;
2335
2336 ret = receive_lttng_error_query(cmd_ctx, *sock, sock_error, &query);
2337 if (ret != LTTNG_OK) {
2338 goto error;
2339 }
2340
2341 ret = cmd_execute_error_query(
2342 &cmd_creds, query, &results, the_notification_thread_handle);
2343 lttng_error_query_destroy(query);
2344 if (ret != LTTNG_OK) {
2345 goto error;
2346 }
2347
2348 LTTNG_ASSERT(results);
2349 ret = lttng_error_query_results_serialize(results, &cmd_ctx->reply_payload);
2350 lttng_error_query_results_destroy(results);
2351 if (ret) {
2352 ERR("Failed to serialize error query result set in reply to `execute error query` command");
2353 ret = LTTNG_ERR_NOMEM;
2354 goto error;
2355 }
2356
2357 payload_size = cmd_ctx->reply_payload.buffer.size - original_payload_size;
2358
2359 update_lttng_msg(cmd_ctx, 0, payload_size);
2360
2361 ret = LTTNG_OK;
2362
2363 break;
2364 }
2365 default:
2366 ret = LTTNG_ERR_UND;
2367 break;
2368 }
2369
2370 error:
2371 if (cmd_ctx->reply_payload.buffer.size == 0) {
2372 DBG("Missing llm header, creating one.");
2373 if (setup_lttng_msg_no_cmd_header(cmd_ctx, nullptr, 0) < 0) {
2374 goto setup_error;
2375 }
2376 }
2377
2378 command_ctx_set_status_code(*cmd_ctx, static_cast<lttng_error_code>(ret));
2379
2380 setup_error:
2381 if (cmd_ctx->session) {
2382 session_unlock(cmd_ctx->session);
2383 session_put(cmd_ctx->session);
2384 cmd_ctx->session = nullptr;
2385 }
2386 if (need_tracing_session) {
2387 session_unlock_list();
2388 }
2389 init_setup_error:
2390 LTTNG_ASSERT(!rcu_read_ongoing());
2391 return ret;
2392 }
2393
2394 static int create_client_sock()
2395 {
2396 int ret, client_sock;
2397
2398 /* Create client tool unix socket */
2399 client_sock = lttcomm_create_unix_sock(the_config.client_unix_sock_path.value);
2400 if (client_sock < 0) {
2401 ERR("Create unix sock failed: %s", the_config.client_unix_sock_path.value);
2402 ret = -1;
2403 goto end;
2404 }
2405
2406 /* Set the cloexec flag */
2407 ret = utils_set_fd_cloexec(client_sock);
2408 if (ret < 0) {
2409 ERR("Unable to set CLOEXEC flag to the client Unix socket (fd: %d). "
2410 "Continuing but note that the consumer daemon will have a "
2411 "reference to this socket on exec()",
2412 client_sock);
2413 }
2414
2415 /* File permission MUST be 660 */
2416 ret = chmod(the_config.client_unix_sock_path.value, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
2417 if (ret < 0) {
2418 ERR("Set file permissions failed: %s", the_config.client_unix_sock_path.value);
2419 PERROR("chmod");
2420 (void) lttcomm_close_unix_sock(client_sock);
2421 ret = -1;
2422 goto end;
2423 }
2424 DBG("Created client socket (fd = %i)", client_sock);
2425 ret = client_sock;
2426 end:
2427 return ret;
2428 }
2429
2430 static void cleanup_client_thread(void *data)
2431 {
2432 struct lttng_pipe *quit_pipe = (lttng_pipe *) data;
2433
2434 lttng_pipe_destroy(quit_pipe);
2435 }
2436
2437 static void thread_init_cleanup(void *data __attribute__((unused)))
2438 {
2439 set_thread_status(false);
2440 }
2441
2442 /*
2443 * This thread manage all clients request using the unix client socket for
2444 * communication.
2445 */
2446 static void *thread_manage_clients(void *data)
2447 {
2448 int sock = -1, ret, i, err = -1;
2449 int sock_error;
2450 uint32_t nb_fd;
2451 struct lttng_poll_event events;
2452 const int client_sock = thread_state.client_sock;
2453 struct lttng_pipe *quit_pipe = (lttng_pipe *) data;
2454 const int thread_quit_pipe_fd = lttng_pipe_get_readfd(quit_pipe);
2455 struct command_ctx cmd_ctx = {};
2456
2457 DBG("[thread] Manage client started");
2458
2459 lttng_payload_init(&cmd_ctx.reply_payload);
2460
2461 is_root = (getuid() == 0);
2462
2463 pthread_cleanup_push(thread_init_cleanup, nullptr);
2464
2465 rcu_register_thread();
2466
2467 health_register(the_health_sessiond, HEALTH_SESSIOND_TYPE_CMD);
2468
2469 health_code_update();
2470
2471 ret = lttcomm_listen_unix_sock(client_sock);
2472 if (ret < 0) {
2473 goto error_listen;
2474 }
2475
2476 /*
2477 * Pass 2 as size here for the thread quit pipe and client_sock. Nothing
2478 * more will be added to this poll set.
2479 */
2480 ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
2481 if (ret < 0) {
2482 goto error_create_poll;
2483 }
2484
2485 /* Add the application registration socket */
2486 ret = lttng_poll_add(&events, client_sock, LPOLLIN | LPOLLPRI);
2487 if (ret < 0) {
2488 goto error;
2489 }
2490
2491 /* Add thread quit pipe */
2492 ret = lttng_poll_add(&events, thread_quit_pipe_fd, LPOLLIN);
2493 if (ret < 0) {
2494 goto error;
2495 }
2496
2497 /* Set state as running. */
2498 set_thread_status(true);
2499 pthread_cleanup_pop(0);
2500
2501 /* This testpoint is after we signal readiness to the parent. */
2502 if (testpoint(sessiond_thread_manage_clients)) {
2503 goto error;
2504 }
2505
2506 if (testpoint(sessiond_thread_manage_clients_before_loop)) {
2507 goto error;
2508 }
2509
2510 health_code_update();
2511
2512 while (true) {
2513 const struct cmd_completion_handler *cmd_completion_handler;
2514
2515 cmd_ctx.creds.uid = UINT32_MAX;
2516 cmd_ctx.creds.gid = UINT32_MAX;
2517 cmd_ctx.creds.pid = 0;
2518 cmd_ctx.session = nullptr;
2519 lttng_payload_clear(&cmd_ctx.reply_payload);
2520 cmd_ctx.lttng_msg_size = 0;
2521
2522 DBG("Accepting client command ...");
2523
2524 /* Inifinite blocking call, waiting for transmission */
2525 restart:
2526 health_poll_entry();
2527 ret = lttng_poll_wait(&events, -1);
2528 health_poll_exit();
2529 if (ret < 0) {
2530 /*
2531 * Restart interrupted system call.
2532 */
2533 if (errno == EINTR) {
2534 goto restart;
2535 }
2536 goto error;
2537 }
2538
2539 nb_fd = ret;
2540
2541 for (i = 0; i < nb_fd; i++) {
2542 /* Fetch once the poll data. */
2543 const auto revents = LTTNG_POLL_GETEV(&events, i);
2544 const auto pollfd = LTTNG_POLL_GETFD(&events, i);
2545
2546 health_code_update();
2547
2548 /* Activity on thread quit pipe, exiting. */
2549 if (pollfd == thread_quit_pipe_fd) {
2550 DBG("Activity on thread quit pipe");
2551 err = 0;
2552 goto exit;
2553 }
2554
2555 /* Event on the registration socket */
2556 if (revents & LPOLLIN) {
2557 continue;
2558 } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
2559 ERR("Client socket poll error");
2560 goto error;
2561 } else {
2562 ERR("Unexpected poll events %u for sock %d", revents, pollfd);
2563 goto error;
2564 }
2565 }
2566
2567 DBG("Wait for client response");
2568
2569 health_code_update();
2570
2571 sock = lttcomm_accept_unix_sock(client_sock);
2572 if (sock < 0) {
2573 goto error;
2574 }
2575
2576 /*
2577 * Set the CLOEXEC flag. Return code is useless because either way, the
2578 * show must go on.
2579 */
2580 (void) utils_set_fd_cloexec(sock);
2581
2582 /* Set socket option for credentials retrieval */
2583 ret = lttcomm_setsockopt_creds_unix_sock(sock);
2584 if (ret < 0) {
2585 goto error;
2586 }
2587
2588 health_code_update();
2589
2590 /*
2591 * Data is received from the lttng client. The struct
2592 * lttcomm_session_msg (lsm) contains the command and data request of
2593 * the client.
2594 */
2595 DBG("Receiving data from client ...");
2596 ret = lttcomm_recv_creds_unix_sock(
2597 sock, &cmd_ctx.lsm, sizeof(struct lttcomm_session_msg), &cmd_ctx.creds);
2598 if (ret != sizeof(struct lttcomm_session_msg)) {
2599 DBG("Incomplete recv() from client... continuing");
2600 ret = close(sock);
2601 if (ret) {
2602 PERROR("close");
2603 }
2604 sock = -1;
2605 continue;
2606 }
2607
2608 health_code_update();
2609
2610 // TODO: Validate cmd_ctx including sanity check for
2611 // security purpose.
2612
2613 rcu_thread_online();
2614 /*
2615 * This function dispatch the work to the kernel or userspace tracer
2616 * libs and fill the lttcomm_lttng_msg data structure of all the needed
2617 * informations for the client. The command context struct contains
2618 * everything this function may needs.
2619 */
2620 try {
2621 ret = process_client_msg(&cmd_ctx, &sock, &sock_error);
2622 rcu_thread_offline();
2623 if (ret < 0) {
2624 if (sock >= 0) {
2625 ret = close(sock);
2626 if (ret) {
2627 PERROR("close");
2628 }
2629 }
2630 sock = -1;
2631 /*
2632 * TODO: Inform client somehow of the fatal error. At
2633 * this point, ret < 0 means that a zmalloc failed
2634 * (ENOMEM). Error detected but still accept
2635 * command, unless a socket error has been
2636 * detected.
2637 */
2638 continue;
2639 }
2640 } catch (const std::bad_alloc& ex) {
2641 WARN_FMT("Failed to allocate memory while handling client request: {}",
2642 ex.what());
2643
2644 /*
2645 * Reset the payload contents as the command may have left them in an
2646 * inconsistent state.
2647 */
2648 (void) setup_empty_lttng_msg(&cmd_ctx);
2649 command_ctx_set_status_code(cmd_ctx, LTTNG_ERR_NOMEM);
2650 } catch (const lttng::ctl::error& ex) {
2651 WARN_FMT("Client request failed: {}", ex.what());
2652
2653 (void) setup_empty_lttng_msg(&cmd_ctx);
2654 command_ctx_set_status_code(cmd_ctx, ex.code());
2655 } catch (const lttng::invalid_argument_error& ex) {
2656 WARN_FMT("Client request failed: {}", ex.what());
2657
2658 (void) setup_empty_lttng_msg(&cmd_ctx);
2659 command_ctx_set_status_code(cmd_ctx, LTTNG_ERR_INVALID);
2660 } catch (const std::exception& ex) {
2661 WARN_FMT("Client request failed: {}", ex.what());
2662
2663 (void) setup_empty_lttng_msg(&cmd_ctx);
2664 command_ctx_set_status_code(cmd_ctx, LTTNG_ERR_UNK);
2665 }
2666
2667 if (ret < LTTNG_OK || ret >= LTTNG_ERR_NR) {
2668 WARN("Command returned an invalid status code, returning unknown error: "
2669 "command type = %s (%d), ret = %d",
2670 lttcomm_sessiond_command_str(
2671 (lttcomm_sessiond_command) cmd_ctx.lsm.cmd_type),
2672 cmd_ctx.lsm.cmd_type,
2673 ret);
2674 ret = LTTNG_ERR_UNK;
2675 }
2676
2677 cmd_completion_handler = cmd_pop_completion_handler();
2678 if (cmd_completion_handler) {
2679 enum lttng_error_code completion_code;
2680
2681 completion_code = cmd_completion_handler->run(cmd_completion_handler->data);
2682 if (completion_code != LTTNG_OK) {
2683 continue;
2684 }
2685 }
2686
2687 health_code_update();
2688
2689 if (sock >= 0) {
2690 struct lttng_payload_view view =
2691 lttng_payload_view_from_payload(&cmd_ctx.reply_payload, 0, -1);
2692 struct lttcomm_lttng_msg *llm =
2693 (typeof(llm)) cmd_ctx.reply_payload.buffer.data;
2694
2695 LTTNG_ASSERT(cmd_ctx.reply_payload.buffer.size >= sizeof(*llm));
2696 LTTNG_ASSERT(cmd_ctx.lttng_msg_size == cmd_ctx.reply_payload.buffer.size);
2697
2698 llm->fd_count = lttng_payload_view_get_fd_handle_count(&view);
2699
2700 DBG("Sending response (size: %d, retcode: %s (%d))",
2701 cmd_ctx.lttng_msg_size,
2702 lttng_strerror(-llm->ret_code),
2703 llm->ret_code);
2704 ret = send_unix_sock(sock, &view);
2705 if (ret < 0) {
2706 ERR("Failed to send data back to client");
2707 }
2708
2709 /* End of transmission */
2710 ret = close(sock);
2711 if (ret) {
2712 PERROR("close");
2713 }
2714 }
2715 sock = -1;
2716
2717 health_code_update();
2718 }
2719
2720 exit:
2721 error:
2722 if (sock >= 0) {
2723 ret = close(sock);
2724 if (ret) {
2725 PERROR("close");
2726 }
2727 }
2728
2729 lttng_poll_clean(&events);
2730
2731 error_listen:
2732 error_create_poll:
2733 unlink(the_config.client_unix_sock_path.value);
2734 ret = close(client_sock);
2735 if (ret) {
2736 PERROR("close");
2737 }
2738
2739 if (err) {
2740 health_error();
2741 ERR("Health error occurred in %s", __func__);
2742 }
2743
2744 health_unregister(the_health_sessiond);
2745
2746 DBG("Client thread dying");
2747 lttng_payload_reset(&cmd_ctx.reply_payload);
2748 rcu_unregister_thread();
2749 return nullptr;
2750 }
2751
2752 static bool shutdown_client_thread(void *thread_data)
2753 {
2754 struct lttng_pipe *client_quit_pipe = (lttng_pipe *) thread_data;
2755 const int write_fd = lttng_pipe_get_writefd(client_quit_pipe);
2756
2757 return notify_thread_pipe(write_fd) == 1;
2758 }
2759
2760 struct lttng_thread *launch_client_thread()
2761 {
2762 bool thread_running;
2763 struct lttng_pipe *client_quit_pipe;
2764 struct lttng_thread *thread = nullptr;
2765 int client_sock_fd = -1;
2766
2767 sem_init(&thread_state.ready, 0, 0);
2768 client_quit_pipe = lttng_pipe_open(FD_CLOEXEC);
2769 if (!client_quit_pipe) {
2770 goto error;
2771 }
2772
2773 client_sock_fd = create_client_sock();
2774 if (client_sock_fd < 0) {
2775 goto error;
2776 }
2777
2778 thread_state.client_sock = client_sock_fd;
2779 thread = lttng_thread_create("Client management",
2780 thread_manage_clients,
2781 shutdown_client_thread,
2782 cleanup_client_thread,
2783 client_quit_pipe);
2784 if (!thread) {
2785 goto error;
2786 }
2787 /* The client thread now owns the client sock fd and the quit pipe. */
2788 client_sock_fd = -1;
2789 client_quit_pipe = nullptr;
2790
2791 /*
2792 * This thread is part of the threads that need to be fully
2793 * initialized before the session daemon is marked as "ready".
2794 */
2795 thread_running = wait_thread_status();
2796 if (!thread_running) {
2797 goto error;
2798 }
2799 return thread;
2800 error:
2801 if (client_sock_fd >= 0) {
2802 if (close(client_sock_fd)) {
2803 PERROR("Failed to close client socket");
2804 }
2805 }
2806 lttng_thread_put(thread);
2807 cleanup_client_thread(client_quit_pipe);
2808 return nullptr;
2809 }
LTTng 2.0 tools and control repository
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