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