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sessiond: introduce ltt_session::locked_ref look-up functions
[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, struct ltt_session *session)
425 {
426 int ret;
427 const char *dir_name;
428 struct consumer_output *consumer;
429
430 LTTNG_ASSERT(session);
431 LTTNG_ASSERT(session->consumer);
432
433 switch (domain) {
434 case LTTNG_DOMAIN_KERNEL:
435 DBG3("Copying tracing session consumer output in kernel session");
436 /*
437 * XXX: We should audit the session creation and what this function
438 * does "extra" in order to avoid a destroy since this function is used
439 * in the domain session creation (kernel and ust) only. Same for UST
440 * domain.
441 */
442 if (session->kernel_session->consumer) {
443 consumer_output_put(session->kernel_session->consumer);
444 }
445 session->kernel_session->consumer = consumer_copy_output(session->consumer);
446 /* Ease our life a bit for the next part */
447 consumer = session->kernel_session->consumer;
448 dir_name = DEFAULT_KERNEL_TRACE_DIR;
449 break;
450 case LTTNG_DOMAIN_JUL:
451 case LTTNG_DOMAIN_LOG4J:
452 case LTTNG_DOMAIN_PYTHON:
453 case LTTNG_DOMAIN_UST:
454 DBG3("Copying tracing session consumer output in UST session");
455 if (session->ust_session->consumer) {
456 consumer_output_put(session->ust_session->consumer);
457 }
458 session->ust_session->consumer = consumer_copy_output(session->consumer);
459 /* Ease our life a bit for the next part */
460 consumer = session->ust_session->consumer;
461 dir_name = DEFAULT_UST_TRACE_DIR;
462 break;
463 default:
464 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
465 goto error;
466 }
467
468 /* Append correct directory to subdir */
469 ret = lttng_strncpy(consumer->domain_subdir, dir_name, sizeof(consumer->domain_subdir));
470 if (ret) {
471 ret = LTTNG_ERR_UNK;
472 goto error;
473 }
474 DBG3("Copy session consumer subdir %s", consumer->domain_subdir);
475 ret = LTTNG_OK;
476
477 error:
478 return ret;
479 }
480
481 /*
482 * Create an UST session and add it to the session ust list.
483 */
484 static int create_ust_session(struct ltt_session *session, const struct lttng_domain *domain)
485 {
486 int ret;
487 struct ltt_ust_session *lus = nullptr;
488
489 LTTNG_ASSERT(session);
490 LTTNG_ASSERT(domain);
491 LTTNG_ASSERT(session->consumer);
492
493 switch (domain->type) {
494 case LTTNG_DOMAIN_JUL:
495 case LTTNG_DOMAIN_LOG4J:
496 case LTTNG_DOMAIN_PYTHON:
497 case LTTNG_DOMAIN_UST:
498 break;
499 default:
500 ERR("Unknown UST domain on create session %d", domain->type);
501 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
502 goto error;
503 }
504
505 DBG("Creating UST session");
506
507 lus = trace_ust_create_session(session->id);
508 if (lus == nullptr) {
509 ret = LTTNG_ERR_UST_SESS_FAIL;
510 goto error;
511 }
512
513 lus->uid = session->uid;
514 lus->gid = session->gid;
515 lus->output_traces = session->output_traces;
516 lus->snapshot_mode = session->snapshot_mode;
517 lus->live_timer_interval = session->live_timer;
518 session->ust_session = lus;
519 if (session->shm_path[0]) {
520 strncpy(lus->root_shm_path, session->shm_path, sizeof(lus->root_shm_path));
521 lus->root_shm_path[sizeof(lus->root_shm_path) - 1] = '\0';
522 strncpy(lus->shm_path, session->shm_path, sizeof(lus->shm_path));
523 lus->shm_path[sizeof(lus->shm_path) - 1] = '\0';
524 strncat(lus->shm_path, "/ust", sizeof(lus->shm_path) - strlen(lus->shm_path) - 1);
525 }
526 /* Copy session output to the newly created UST session */
527 ret = copy_session_consumer(domain->type, session);
528 if (ret != LTTNG_OK) {
529 goto error;
530 }
531
532 return LTTNG_OK;
533
534 error:
535 free(lus);
536 session->ust_session = nullptr;
537 return ret;
538 }
539
540 /*
541 * Create a kernel tracer session then create the default channel.
542 */
543 static int create_kernel_session(struct ltt_session *session)
544 {
545 int ret;
546
547 DBG("Creating kernel session");
548
549 ret = kernel_create_session(session);
550 if (ret < 0) {
551 ret = LTTNG_ERR_KERN_SESS_FAIL;
552 goto error_create;
553 }
554
555 /* Code flow safety */
556 LTTNG_ASSERT(session->kernel_session);
557
558 /* Copy session output to the newly created Kernel session */
559 ret = copy_session_consumer(LTTNG_DOMAIN_KERNEL, session);
560 if (ret != LTTNG_OK) {
561 goto error;
562 }
563
564 session->kernel_session->uid = session->uid;
565 session->kernel_session->gid = session->gid;
566 session->kernel_session->output_traces = session->output_traces;
567 session->kernel_session->snapshot_mode = session->snapshot_mode;
568 session->kernel_session->is_live_session = session->live_timer != 0;
569
570 return LTTNG_OK;
571
572 error:
573 trace_kernel_destroy_session(session->kernel_session);
574 session->kernel_session = nullptr;
575 error_create:
576 return ret;
577 }
578
579 /*
580 * Count number of session permitted by uid/gid.
581 */
582 static unsigned int lttng_sessions_count(uid_t uid, gid_t gid __attribute__((unused)))
583 {
584 unsigned int i = 0;
585 struct ltt_session *session;
586 const struct ltt_session_list *session_list = session_get_list();
587
588 DBG("Counting number of available session for UID %d", uid);
589 cds_list_for_each_entry (session, &session_list->head, list) {
590 if (!session_get(session)) {
591 continue;
592 }
593 session_lock(session);
594 /* Only count the sessions the user can control. */
595 if (session_access_ok(session, uid) && !session->destroyed) {
596 i++;
597 }
598 session_unlock(session);
599 session_put(session);
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 null for commands that don't
1115 * have a target session.
1116 */
1117 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 =
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.get());
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 lttng_domain domain = cmd_ctx->lsm.domain;
1288 ret = create_ust_session(target_session.get(), &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.get(),
1395 LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds)) ||
1396 target_session->destroyed) {
1397 ret = LTTNG_ERR_EPERM;
1398 goto error;
1399 }
1400 }
1401
1402 /*
1403 * Send relayd information to consumer as soon as we have a domain and a
1404 * session defined.
1405 */
1406 if (target_session && need_domain) {
1407 /*
1408 * Setup relayd if not done yet. If the relayd information was already
1409 * sent to the consumer, this call will gracefully return.
1410 */
1411 ret = cmd_setup_relayd(target_session.get());
1412 if (ret != LTTNG_OK) {
1413 goto error;
1414 }
1415 }
1416
1417 /* Process by command type */
1418 switch (cmd_ctx->lsm.cmd_type) {
1419 case LTTCOMM_SESSIOND_COMMAND_ADD_CONTEXT:
1420 {
1421 struct lttng_event_context *event_context = nullptr;
1422 const enum lttng_error_code ret_code =
1423 receive_lttng_event_context(cmd_ctx, *sock, sock_error, &event_context);
1424
1425 if (ret_code != LTTNG_OK) {
1426 ret = (int) ret_code;
1427 goto error;
1428 }
1429
1430 ret = cmd_add_context(
1431 cmd_ctx, target_session, event_context, the_kernel_poll_pipe[1]);
1432 lttng_event_context_destroy(event_context);
1433 break;
1434 }
1435 case LTTCOMM_SESSIOND_COMMAND_DISABLE_CHANNEL:
1436 {
1437 ret = cmd_disable_channel(target_session.get(),
1438 cmd_ctx->lsm.domain.type,
1439 cmd_ctx->lsm.u.disable.channel_name);
1440 break;
1441 }
1442 case LTTCOMM_SESSIOND_COMMAND_ENABLE_CHANNEL:
1443 {
1444 ret = cmd_enable_channel(cmd_ctx, target_session, *sock, the_kernel_poll_pipe[1]);
1445 break;
1446 }
1447 case LTTCOMM_SESSIOND_COMMAND_PROCESS_ATTR_TRACKER_ADD_INCLUDE_VALUE:
1448 case LTTCOMM_SESSIOND_COMMAND_PROCESS_ATTR_TRACKER_REMOVE_INCLUDE_VALUE:
1449 {
1450 struct lttng_dynamic_buffer payload;
1451 struct lttng_buffer_view payload_view;
1452 const bool add_value = cmd_ctx->lsm.cmd_type ==
1453 LTTCOMM_SESSIOND_COMMAND_PROCESS_ATTR_TRACKER_ADD_INCLUDE_VALUE;
1454 const size_t name_len =
1455 cmd_ctx->lsm.u.process_attr_tracker_add_remove_include_value.name_len;
1456 const enum lttng_domain_type domain_type =
1457 (enum lttng_domain_type) cmd_ctx->lsm.domain.type;
1458 const enum lttng_process_attr process_attr =
1459 (enum lttng_process_attr) cmd_ctx->lsm.u
1460 .process_attr_tracker_add_remove_include_value.process_attr;
1461 const enum lttng_process_attr_value_type value_type =
1462 (enum lttng_process_attr_value_type) cmd_ctx->lsm.u
1463 .process_attr_tracker_add_remove_include_value.value_type;
1464 struct process_attr_value *value;
1465 enum lttng_error_code ret_code;
1466 long login_name_max;
1467
1468 login_name_max = sysconf(_SC_LOGIN_NAME_MAX);
1469 if (login_name_max < 0) {
1470 PERROR("Failed to get _SC_LOGIN_NAME_MAX system configuration");
1471 ret = LTTNG_ERR_INVALID;
1472 goto error;
1473 }
1474
1475 /* Receive remaining variable length payload if applicable. */
1476 if (name_len > login_name_max) {
1477 /*
1478 * POSIX mandates user and group names that are at least
1479 * 8 characters long. Note that although shadow-utils
1480 * (useradd, groupaadd, etc.) use 32 chars as their
1481 * limit (from bits/utmp.h, UT_NAMESIZE),
1482 * LOGIN_NAME_MAX is defined to 256.
1483 */
1484 ERR("Rejecting process attribute tracker value %s as the provided exceeds the maximal allowed length: argument length = %zu, maximal length = %ld",
1485 add_value ? "addition" : "removal",
1486 name_len,
1487 login_name_max);
1488 ret = LTTNG_ERR_INVALID;
1489 goto error;
1490 }
1491
1492 lttng_dynamic_buffer_init(&payload);
1493 if (name_len != 0) {
1494 /*
1495 * Receive variable payload for user/group name
1496 * arguments.
1497 */
1498 ret = lttng_dynamic_buffer_set_size(&payload, name_len);
1499 if (ret) {
1500 ERR("Failed to allocate buffer to receive payload of %s process attribute tracker value argument",
1501 add_value ? "add" : "remove");
1502 ret = LTTNG_ERR_NOMEM;
1503 goto error_add_remove_tracker_value;
1504 }
1505
1506 ret = lttcomm_recv_unix_sock(*sock, payload.data, name_len);
1507 if (ret <= 0) {
1508 ERR("Failed to receive payload of %s process attribute tracker value argument",
1509 add_value ? "add" : "remove");
1510 *sock_error = 1;
1511 ret = LTTNG_ERR_INVALID_PROTOCOL;
1512 goto error_add_remove_tracker_value;
1513 }
1514 }
1515
1516 payload_view = lttng_buffer_view_from_dynamic_buffer(&payload, 0, name_len);
1517 if (name_len > 0 && !lttng_buffer_view_is_valid(&payload_view)) {
1518 ret = LTTNG_ERR_INVALID_PROTOCOL;
1519 goto error_add_remove_tracker_value;
1520 }
1521
1522 /*
1523 * Validate the value type and domains are legal for the process
1524 * attribute tracker that is specified and convert the value to
1525 * add/remove to the internal sessiond representation.
1526 */
1527 ret_code = process_attr_value_from_comm(
1528 domain_type,
1529 process_attr,
1530 value_type,
1531 &cmd_ctx->lsm.u.process_attr_tracker_add_remove_include_value.integral_value,
1532 &payload_view,
1533 &value);
1534 if (ret_code != LTTNG_OK) {
1535 ret = ret_code;
1536 goto error_add_remove_tracker_value;
1537 }
1538
1539 if (add_value) {
1540 ret = cmd_process_attr_tracker_inclusion_set_add_value(
1541 target_session.get(), domain_type, process_attr, value);
1542 } else {
1543 ret = cmd_process_attr_tracker_inclusion_set_remove_value(
1544 target_session.get(), domain_type, process_attr, value);
1545 }
1546 process_attr_value_destroy(value);
1547 error_add_remove_tracker_value:
1548 lttng_dynamic_buffer_reset(&payload);
1549 break;
1550 }
1551 case LTTCOMM_SESSIOND_COMMAND_PROCESS_ATTR_TRACKER_GET_POLICY:
1552 {
1553 enum lttng_tracking_policy tracking_policy;
1554 const enum lttng_domain_type domain_type =
1555 (enum lttng_domain_type) cmd_ctx->lsm.domain.type;
1556 const enum lttng_process_attr process_attr =
1557 (enum lttng_process_attr) cmd_ctx->lsm.u
1558 .process_attr_tracker_get_tracking_policy.process_attr;
1559
1560 ret = cmd_process_attr_tracker_get_tracking_policy(
1561 target_session.get(), domain_type, process_attr, &tracking_policy);
1562 if (ret != LTTNG_OK) {
1563 goto error;
1564 }
1565
1566 uint32_t tracking_policy_u32 = tracking_policy;
1567 setup_lttng_msg_no_cmd_header(cmd_ctx, &tracking_policy_u32, sizeof(uint32_t));
1568
1569 ret = LTTNG_OK;
1570 break;
1571 }
1572 case LTTCOMM_SESSIOND_COMMAND_PROCESS_ATTR_TRACKER_SET_POLICY:
1573 {
1574 const enum lttng_tracking_policy tracking_policy =
1575 (enum lttng_tracking_policy) cmd_ctx->lsm.u
1576 .process_attr_tracker_set_tracking_policy.tracking_policy;
1577 const enum lttng_domain_type domain_type =
1578 (enum lttng_domain_type) cmd_ctx->lsm.domain.type;
1579 const enum lttng_process_attr process_attr =
1580 (enum lttng_process_attr) cmd_ctx->lsm.u
1581 .process_attr_tracker_set_tracking_policy.process_attr;
1582
1583 ret = cmd_process_attr_tracker_set_tracking_policy(
1584 target_session.get(), domain_type, process_attr, tracking_policy);
1585 if (ret != LTTNG_OK) {
1586 goto error;
1587 }
1588 break;
1589 }
1590 case LTTCOMM_SESSIOND_COMMAND_PROCESS_ATTR_TRACKER_GET_INCLUSION_SET:
1591 {
1592 struct lttng_process_attr_values *values;
1593 struct lttng_dynamic_buffer reply;
1594 const enum lttng_domain_type domain_type =
1595 (enum lttng_domain_type) cmd_ctx->lsm.domain.type;
1596 const enum lttng_process_attr process_attr =
1597 (enum lttng_process_attr)
1598 cmd_ctx->lsm.u.process_attr_tracker_get_inclusion_set.process_attr;
1599
1600 ret = cmd_process_attr_tracker_get_inclusion_set(
1601 target_session.get(), domain_type, process_attr, &values);
1602 if (ret != LTTNG_OK) {
1603 goto error;
1604 }
1605
1606 lttng_dynamic_buffer_init(&reply);
1607 ret = lttng_process_attr_values_serialize(values, &reply);
1608 if (ret < 0) {
1609 goto error_tracker_get_inclusion_set;
1610 }
1611
1612 setup_lttng_msg_no_cmd_header(cmd_ctx, reply.data, reply.size);
1613 ret = LTTNG_OK;
1614
1615 error_tracker_get_inclusion_set:
1616 lttng_process_attr_values_destroy(values);
1617 lttng_dynamic_buffer_reset(&reply);
1618 break;
1619 }
1620 case LTTCOMM_SESSIOND_COMMAND_ENABLE_EVENT:
1621 case LTTCOMM_SESSIOND_COMMAND_DISABLE_EVENT:
1622 {
1623 struct lttng_event *event;
1624 char *filter_expression;
1625 struct lttng_event_exclusion *exclusions;
1626 struct lttng_bytecode *bytecode;
1627 const enum lttng_error_code ret_code = receive_lttng_event(cmd_ctx,
1628 *sock,
1629 sock_error,
1630 &event,
1631 &filter_expression,
1632 &bytecode,
1633 &exclusions);
1634
1635 if (ret_code != LTTNG_OK) {
1636 ret = (int) ret_code;
1637 goto error;
1638 }
1639
1640 /*
1641 * Ownership of filter_expression, exclusions, and bytecode is
1642 * always transferred.
1643 */
1644 ret = cmd_ctx->lsm.cmd_type == LTTCOMM_SESSIOND_COMMAND_ENABLE_EVENT ?
1645 cmd_enable_event(cmd_ctx,
1646 target_session,
1647 event,
1648 filter_expression,
1649 exclusions,
1650 bytecode,
1651 the_kernel_poll_pipe[1]) :
1652 cmd_disable_event(cmd_ctx,
1653 target_session,
1654 event,
1655 filter_expression,
1656 bytecode,
1657 exclusions);
1658 lttng_event_destroy(event);
1659 break;
1660 }
1661 case LTTCOMM_SESSIOND_COMMAND_LIST_TRACEPOINTS:
1662 {
1663 enum lttng_error_code ret_code;
1664 size_t original_payload_size;
1665 size_t payload_size;
1666 const size_t command_header_size = sizeof(struct lttcomm_list_command_header);
1667
1668 setup_empty_lttng_msg(cmd_ctx);
1669
1670 original_payload_size = cmd_ctx->reply_payload.buffer.size;
1671
1672 list_lock = lttng::sessiond::lock_session_list();
1673 ret_code = cmd_list_tracepoints(cmd_ctx->lsm.domain.type, &cmd_ctx->reply_payload);
1674 if (ret_code != LTTNG_OK) {
1675 ret = (int) ret_code;
1676 goto error;
1677 }
1678
1679 payload_size = cmd_ctx->reply_payload.buffer.size - command_header_size -
1680 original_payload_size;
1681 update_lttng_msg(cmd_ctx, command_header_size, payload_size);
1682
1683 ret = LTTNG_OK;
1684 break;
1685 }
1686 case LTTCOMM_SESSIOND_COMMAND_LIST_TRACEPOINT_FIELDS:
1687 {
1688 enum lttng_error_code ret_code;
1689 size_t original_payload_size;
1690 size_t payload_size;
1691 const size_t command_header_size = sizeof(struct lttcomm_list_command_header);
1692
1693 setup_empty_lttng_msg(cmd_ctx);
1694
1695 original_payload_size = cmd_ctx->reply_payload.buffer.size;
1696
1697 list_lock = lttng::sessiond::lock_session_list();
1698 ret_code = cmd_list_tracepoint_fields(cmd_ctx->lsm.domain.type,
1699 &cmd_ctx->reply_payload);
1700
1701 if (ret_code != LTTNG_OK) {
1702 ret = (int) ret_code;
1703 goto error;
1704 }
1705
1706 payload_size = cmd_ctx->reply_payload.buffer.size - command_header_size -
1707 original_payload_size;
1708 update_lttng_msg(cmd_ctx, command_header_size, payload_size);
1709
1710 ret = LTTNG_OK;
1711 break;
1712 }
1713 case LTTCOMM_SESSIOND_COMMAND_LIST_SYSCALLS:
1714 {
1715 enum lttng_error_code ret_code;
1716 size_t original_payload_size;
1717 size_t payload_size;
1718 const size_t command_header_size = sizeof(struct lttcomm_list_command_header);
1719
1720 setup_empty_lttng_msg(cmd_ctx);
1721
1722 original_payload_size = cmd_ctx->reply_payload.buffer.size;
1723
1724 ret_code = cmd_list_syscalls(&cmd_ctx->reply_payload);
1725 if (ret_code != LTTNG_OK) {
1726 ret = (int) ret_code;
1727 goto error;
1728 }
1729
1730 payload_size = cmd_ctx->reply_payload.buffer.size - command_header_size -
1731 original_payload_size;
1732 update_lttng_msg(cmd_ctx, command_header_size, payload_size);
1733
1734 ret = LTTNG_OK;
1735 break;
1736 }
1737 case LTTCOMM_SESSIOND_COMMAND_SET_CONSUMER_URI:
1738 {
1739 size_t nb_uri, len;
1740 struct lttng_uri *uris;
1741
1742 nb_uri = cmd_ctx->lsm.u.uri.size;
1743 len = nb_uri * sizeof(struct lttng_uri);
1744
1745 if (nb_uri == 0) {
1746 ret = LTTNG_ERR_INVALID;
1747 goto error;
1748 }
1749
1750 uris = calloc<lttng_uri>(nb_uri);
1751 if (uris == nullptr) {
1752 ret = LTTNG_ERR_FATAL;
1753 goto error;
1754 }
1755
1756 /* Receive variable len data */
1757 DBG("Receiving %zu URI(s) from client ...", nb_uri);
1758 ret = lttcomm_recv_unix_sock(*sock, uris, len);
1759 if (ret <= 0) {
1760 DBG("No URIs received from client... continuing");
1761 *sock_error = 1;
1762 ret = LTTNG_ERR_SESSION_FAIL;
1763 free(uris);
1764 goto error;
1765 }
1766
1767 ret = cmd_set_consumer_uri(target_session.get(), nb_uri, uris);
1768 free(uris);
1769 if (ret != LTTNG_OK) {
1770 goto error;
1771 }
1772
1773 break;
1774 }
1775 case LTTCOMM_SESSIOND_COMMAND_START_TRACE:
1776 {
1777 /*
1778 * On the first start, if we have a kernel session and we have
1779 * enabled time or size-based rotations, we have to make sure
1780 * the kernel tracer supports it.
1781 */
1782 if (!target_session->has_been_started && target_session->kernel_session &&
1783 (target_session->rotate_timer_period || target_session->rotate_size) &&
1784 !check_rotate_compatible()) {
1785 DBG("Kernel tracer version is not compatible with the rotation feature");
1786 ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
1787 goto error;
1788 }
1789 ret = cmd_start_trace(target_session.get());
1790 break;
1791 }
1792 case LTTCOMM_SESSIOND_COMMAND_STOP_TRACE:
1793 {
1794 ret = cmd_stop_trace(target_session.get());
1795 break;
1796 }
1797 case LTTCOMM_SESSIOND_COMMAND_DESTROY_SESSION:
1798 {
1799 ret = cmd_destroy_session(target_session.get(), sock);
1800 break;
1801 }
1802 case LTTCOMM_SESSIOND_COMMAND_LIST_DOMAINS:
1803 {
1804 ssize_t nb_dom;
1805 struct lttng_domain *domains = nullptr;
1806
1807 nb_dom = cmd_list_domains(target_session.get(), &domains);
1808 if (nb_dom < 0) {
1809 /* Return value is a negative lttng_error_code. */
1810 ret = -nb_dom;
1811 goto error;
1812 }
1813
1814 setup_lttng_msg_no_cmd_header(
1815 cmd_ctx, domains, nb_dom * sizeof(struct lttng_domain));
1816 free(domains);
1817
1818 ret = LTTNG_OK;
1819 break;
1820 }
1821 case LTTCOMM_SESSIOND_COMMAND_LIST_CHANNELS:
1822 {
1823 enum lttng_error_code ret_code;
1824 size_t original_payload_size;
1825 size_t payload_size;
1826 const size_t command_header_size = sizeof(struct lttcomm_list_command_header);
1827
1828 setup_empty_lttng_msg(cmd_ctx);
1829
1830 original_payload_size = cmd_ctx->reply_payload.buffer.size;
1831
1832 ret_code = cmd_list_channels(
1833 cmd_ctx->lsm.domain.type, target_session.get(), &cmd_ctx->reply_payload);
1834 if (ret_code != LTTNG_OK) {
1835 ret = (int) ret_code;
1836 goto error;
1837 }
1838
1839 payload_size = cmd_ctx->reply_payload.buffer.size - command_header_size -
1840 original_payload_size;
1841 update_lttng_msg(cmd_ctx, command_header_size, payload_size);
1842
1843 ret = LTTNG_OK;
1844 break;
1845 }
1846 case LTTCOMM_SESSIOND_COMMAND_LIST_EVENTS:
1847 {
1848 enum lttng_error_code ret_code;
1849 size_t original_payload_size;
1850 size_t payload_size;
1851 const size_t command_header_size = sizeof(struct lttcomm_list_command_header);
1852
1853 setup_empty_lttng_msg(cmd_ctx);
1854
1855 original_payload_size = cmd_ctx->reply_payload.buffer.size;
1856
1857 ret_code = cmd_list_events(cmd_ctx->lsm.domain.type,
1858 target_session.get(),
1859 cmd_ctx->lsm.u.list.channel_name,
1860 &cmd_ctx->reply_payload);
1861 if (ret_code != LTTNG_OK) {
1862 ret = (int) ret_code;
1863 goto error;
1864 }
1865
1866 payload_size = cmd_ctx->reply_payload.buffer.size - command_header_size -
1867 original_payload_size;
1868 update_lttng_msg(cmd_ctx, command_header_size, payload_size);
1869
1870 ret = LTTNG_OK;
1871 break;
1872 }
1873 case LTTCOMM_SESSIOND_COMMAND_LIST_SESSIONS:
1874 {
1875 unsigned int nr_sessions;
1876 lttng_session *sessions_payload = nullptr;
1877 size_t payload_len = 0;
1878
1879 list_lock = lttng::sessiond::lock_session_list();
1880 nr_sessions = lttng_sessions_count(LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
1881 LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds));
1882
1883 if (nr_sessions > 0) {
1884 payload_len = (sizeof(struct lttng_session) * nr_sessions) +
1885 (sizeof(struct lttng_session_extended) * nr_sessions);
1886 sessions_payload = zmalloc<lttng_session>(payload_len);
1887 if (!sessions_payload) {
1888 LTTNG_THROW_ALLOCATION_FAILURE_ERROR(
1889 "Failed to allocate session list reply payload",
1890 payload_len);
1891 }
1892
1893 cmd_list_lttng_sessions(sessions_payload,
1894 nr_sessions,
1895 LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
1896 LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds));
1897 }
1898
1899 setup_lttng_msg_no_cmd_header(cmd_ctx, sessions_payload, payload_len);
1900 free(sessions_payload);
1901
1902 ret = LTTNG_OK;
1903 break;
1904 }
1905 case LTTCOMM_SESSIOND_COMMAND_REGISTER_CONSUMER:
1906 {
1907 struct consumer_data *cdata;
1908
1909 switch (cmd_ctx->lsm.domain.type) {
1910 case LTTNG_DOMAIN_KERNEL:
1911 cdata = &the_kconsumer_data;
1912 break;
1913 default:
1914 ret = LTTNG_ERR_UND;
1915 goto error;
1916 }
1917
1918 ret = cmd_register_consumer(target_session.get(),
1919 cmd_ctx->lsm.domain.type,
1920 cmd_ctx->lsm.u.reg.path,
1921 cdata);
1922 break;
1923 }
1924 case LTTCOMM_SESSIOND_COMMAND_KERNEL_TRACER_STATUS:
1925 {
1926 uint32_t u_status;
1927 enum lttng_kernel_tracer_status status;
1928
1929 ret = cmd_kernel_tracer_status(&status);
1930 if (ret != LTTNG_OK) {
1931 goto error;
1932 }
1933
1934 u_status = (uint32_t) status;
1935 setup_lttng_msg_no_cmd_header(cmd_ctx, &u_status, 4);
1936
1937 ret = LTTNG_OK;
1938 break;
1939 }
1940 case LTTCOMM_SESSIOND_COMMAND_DATA_PENDING:
1941 {
1942 int pending_ret;
1943 uint8_t pending_ret_byte;
1944
1945 pending_ret = cmd_data_pending(target_session.get());
1946
1947 /*
1948 * FIXME
1949 *
1950 * This function may returns 0 or 1 to indicate whether or not
1951 * there is data pending. In case of error, it should return an
1952 * LTTNG_ERR code. However, some code paths may still return
1953 * a nondescript error code, which we handle by returning an
1954 * "unknown" error.
1955 */
1956 if (pending_ret == 0 || pending_ret == 1) {
1957 /*
1958 * ret will be set to LTTNG_OK at the end of
1959 * this function.
1960 */
1961 } else if (pending_ret <= LTTNG_OK || pending_ret >= LTTNG_ERR_NR) {
1962 ret = LTTNG_ERR_UNK;
1963 goto error;
1964 } else {
1965 ret = pending_ret;
1966 goto error;
1967 }
1968
1969 pending_ret_byte = (uint8_t) pending_ret;
1970
1971 /* 1 byte to return whether or not data is pending */
1972 setup_lttng_msg_no_cmd_header(cmd_ctx, &pending_ret_byte, 1);
1973
1974 ret = LTTNG_OK;
1975 break;
1976 }
1977 case LTTCOMM_SESSIOND_COMMAND_SNAPSHOT_ADD_OUTPUT:
1978 {
1979 uint32_t snapshot_id;
1980 struct lttcomm_lttng_output_id reply;
1981 lttng_snapshot_output output = cmd_ctx->lsm.u.snapshot_output.output;
1982
1983 ret = cmd_snapshot_add_output(target_session.get(), &output, &snapshot_id);
1984 if (ret != LTTNG_OK) {
1985 goto error;
1986 }
1987 reply.id = snapshot_id;
1988
1989 setup_lttng_msg_no_cmd_header(cmd_ctx, &reply, sizeof(reply));
1990
1991 /* Copy output list into message payload */
1992 ret = LTTNG_OK;
1993 break;
1994 }
1995 case LTTCOMM_SESSIOND_COMMAND_SNAPSHOT_DEL_OUTPUT:
1996 {
1997 lttng_snapshot_output output = cmd_ctx->lsm.u.snapshot_output.output;
1998 ret = cmd_snapshot_del_output(target_session.get(), &output);
1999 break;
2000 }
2001 case LTTCOMM_SESSIOND_COMMAND_SNAPSHOT_LIST_OUTPUT:
2002 {
2003 ssize_t nb_output;
2004 struct lttng_snapshot_output *outputs = nullptr;
2005
2006 nb_output = cmd_snapshot_list_outputs(target_session.get(), &outputs);
2007 if (nb_output < 0) {
2008 ret = -nb_output;
2009 goto error;
2010 }
2011
2012 LTTNG_ASSERT((nb_output > 0 && outputs) || nb_output == 0);
2013 setup_lttng_msg_no_cmd_header(
2014 cmd_ctx, outputs, nb_output * sizeof(struct lttng_snapshot_output));
2015 free(outputs);
2016
2017 ret = LTTNG_OK;
2018 break;
2019 }
2020 case LTTCOMM_SESSIOND_COMMAND_SNAPSHOT_RECORD:
2021 {
2022 lttng_snapshot_output output = cmd_ctx->lsm.u.snapshot_record.output;
2023 ret = cmd_snapshot_record(target_session.get(), &output, 0); // RFC: set to zero
2024 // since it's ignored
2025 // by
2026 // cmd_snapshot_record
2027 break;
2028 }
2029 case LTTCOMM_SESSIOND_COMMAND_CREATE_SESSION_EXT:
2030 {
2031 struct lttng_dynamic_buffer payload;
2032
2033 lttng_dynamic_buffer_init(&payload);
2034
2035 lttng::ctl::session_descriptor reply_session_descriptor = [cmd_ctx, sock]() {
2036 lttng_session_descriptor *raw_descriptor;
2037 const auto create_ret = cmd_create_session(cmd_ctx, *sock, &raw_descriptor);
2038 if (create_ret != LTTNG_OK) {
2039 LTTNG_THROW_CTL("Failed to create session", create_ret);
2040 }
2041
2042 return lttng::ctl::session_descriptor(raw_descriptor);
2043 }();
2044
2045 ret = lttng_session_descriptor_serialize(reply_session_descriptor.get(), &payload);
2046 if (ret) {
2047 LTTNG_THROW_CTL(
2048 "Failed to serialize session descriptor in reply to \"create session\" command",
2049 LTTNG_ERR_NOMEM);
2050 }
2051
2052 setup_lttng_msg_no_cmd_header(cmd_ctx, payload.data, payload.size);
2053
2054 lttng_dynamic_buffer_reset(&payload);
2055 ret = LTTNG_OK;
2056 break;
2057 }
2058 case LTTCOMM_SESSIOND_COMMAND_SAVE_SESSION:
2059 {
2060 ret = cmd_save_sessions(&cmd_ctx->lsm.u.save_session.attr, &cmd_ctx->creds);
2061 break;
2062 }
2063 case LTTCOMM_SESSIOND_COMMAND_SET_SESSION_SHM_PATH:
2064 {
2065 ret = cmd_set_session_shm_path(target_session.get(),
2066 cmd_ctx->lsm.u.set_shm_path.shm_path);
2067 break;
2068 }
2069 case LTTCOMM_SESSIOND_COMMAND_REGENERATE_METADATA:
2070 {
2071 ret = cmd_regenerate_metadata(target_session.get());
2072 break;
2073 }
2074 case LTTCOMM_SESSIOND_COMMAND_REGENERATE_STATEDUMP:
2075 {
2076 ret = cmd_regenerate_statedump(target_session.get());
2077 break;
2078 }
2079 case LTTCOMM_SESSIOND_COMMAND_REGISTER_TRIGGER:
2080 {
2081 size_t original_reply_payload_size;
2082 size_t reply_payload_size;
2083 const struct lttng_credentials cmd_creds = {
2084 .uid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.uid),
2085 .gid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.gid),
2086 };
2087
2088 setup_empty_lttng_msg(cmd_ctx);
2089
2090 auto payload_trigger = receive_lttng_trigger(cmd_ctx, *sock, sock_error);
2091 if (ret != LTTNG_OK) {
2092 goto error;
2093 }
2094
2095 original_reply_payload_size = cmd_ctx->reply_payload.buffer.size;
2096
2097 auto return_trigger =
2098 cmd_register_trigger(&cmd_creds,
2099 payload_trigger.get(),
2100 cmd_ctx->lsm.u.trigger.is_trigger_anonymous,
2101 the_notification_thread_handle);
2102
2103 ret = lttng_trigger_serialize(return_trigger.get(), &cmd_ctx->reply_payload);
2104 if (ret) {
2105 LTTNG_THROW_CTL(
2106 "Failed to serialize trigger in reply to \"register trigger\" command",
2107 LTTNG_ERR_NOMEM);
2108 }
2109
2110 reply_payload_size =
2111 cmd_ctx->reply_payload.buffer.size - original_reply_payload_size;
2112
2113 update_lttng_msg(cmd_ctx, 0, reply_payload_size);
2114
2115 ret = LTTNG_OK;
2116 break;
2117 }
2118 case LTTCOMM_SESSIOND_COMMAND_UNREGISTER_TRIGGER:
2119 {
2120 const struct lttng_credentials cmd_creds = {
2121 .uid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.uid),
2122 .gid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.gid),
2123 };
2124
2125 auto payload_trigger = receive_lttng_trigger(cmd_ctx, *sock, sock_error);
2126
2127 ret = cmd_unregister_trigger(
2128 &cmd_creds, payload_trigger.get(), the_notification_thread_handle);
2129 break;
2130 }
2131 case LTTCOMM_SESSIOND_COMMAND_ROTATE_SESSION:
2132 {
2133 struct lttng_rotate_session_return rotate_return;
2134
2135 DBG("Client rotate session \"%s\"", target_session->name);
2136
2137 memset(&rotate_return, 0, sizeof(rotate_return));
2138 if (target_session->kernel_session && !check_rotate_compatible()) {
2139 DBG("Kernel tracer version is not compatible with the rotation feature");
2140 ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
2141 goto error;
2142 }
2143
2144 ret = cmd_rotate_session(target_session.get(),
2145 &rotate_return,
2146 false,
2147 LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED);
2148 if (ret < 0) {
2149 ret = -ret;
2150 goto error;
2151 }
2152
2153 setup_lttng_msg_no_cmd_header(cmd_ctx, &rotate_return, sizeof(rotate_return));
2154
2155 ret = LTTNG_OK;
2156 break;
2157 }
2158 case LTTCOMM_SESSIOND_COMMAND_ROTATION_GET_INFO:
2159 {
2160 struct lttng_rotation_get_info_return get_info_return;
2161
2162 memset(&get_info_return, 0, sizeof(get_info_return));
2163 ret = cmd_rotate_get_info(target_session.get(),
2164 &get_info_return,
2165 cmd_ctx->lsm.u.get_rotation_info.rotation_id);
2166 if (ret < 0) {
2167 ret = -ret;
2168 goto error;
2169 }
2170
2171 setup_lttng_msg_no_cmd_header(cmd_ctx, &get_info_return, sizeof(get_info_return));
2172
2173 ret = LTTNG_OK;
2174 break;
2175 }
2176 case LTTCOMM_SESSIOND_COMMAND_ROTATION_SET_SCHEDULE:
2177 {
2178 bool set_schedule;
2179 enum lttng_rotation_schedule_type schedule_type;
2180 uint64_t value;
2181
2182 if (target_session->kernel_session && !check_rotate_compatible()) {
2183 DBG("Kernel tracer version does not support session rotations");
2184 ret = LTTNG_ERR_ROTATION_WRONG_VERSION;
2185 goto error;
2186 }
2187
2188 set_schedule = cmd_ctx->lsm.u.rotation_set_schedule.set == 1;
2189 schedule_type = (enum lttng_rotation_schedule_type)
2190 cmd_ctx->lsm.u.rotation_set_schedule.type;
2191 value = cmd_ctx->lsm.u.rotation_set_schedule.value;
2192
2193 ret = cmd_rotation_set_schedule(
2194 target_session.get(), set_schedule, schedule_type, value);
2195 if (ret != LTTNG_OK) {
2196 goto error;
2197 }
2198
2199 break;
2200 }
2201 case LTTCOMM_SESSIOND_COMMAND_SESSION_LIST_ROTATION_SCHEDULES:
2202 {
2203 lttng_session_list_schedules_return schedules;
2204
2205 schedules.periodic.set = !!target_session->rotate_timer_period;
2206 schedules.periodic.value = target_session->rotate_timer_period;
2207 schedules.size.set = !!target_session->rotate_size;
2208 schedules.size.value = target_session->rotate_size;
2209
2210 setup_lttng_msg_no_cmd_header(cmd_ctx, &schedules, sizeof(schedules));
2211
2212 ret = LTTNG_OK;
2213 break;
2214 }
2215 case LTTCOMM_SESSIOND_COMMAND_CLEAR_SESSION:
2216 {
2217 ret = cmd_clear_session(target_session.get(), sock);
2218 break;
2219 }
2220 case LTTCOMM_SESSIOND_COMMAND_LIST_TRIGGERS:
2221 {
2222 struct lttng_triggers *return_triggers = nullptr;
2223 size_t original_payload_size;
2224 size_t payload_size;
2225
2226 setup_empty_lttng_msg(cmd_ctx);
2227
2228 original_payload_size = cmd_ctx->reply_payload.buffer.size;
2229
2230 ret = cmd_list_triggers(cmd_ctx, the_notification_thread_handle, &return_triggers);
2231 if (ret != LTTNG_OK) {
2232 goto error;
2233 }
2234
2235 LTTNG_ASSERT(return_triggers);
2236 ret = lttng_triggers_serialize(return_triggers, &cmd_ctx->reply_payload);
2237 lttng_triggers_destroy(return_triggers);
2238 if (ret) {
2239 ERR("Failed to serialize triggers in reply to `list triggers` command");
2240 ret = LTTNG_ERR_NOMEM;
2241 goto error;
2242 }
2243
2244 payload_size = cmd_ctx->reply_payload.buffer.size - original_payload_size;
2245
2246 update_lttng_msg(cmd_ctx, 0, payload_size);
2247
2248 ret = LTTNG_OK;
2249 break;
2250 }
2251 case LTTCOMM_SESSIOND_COMMAND_EXECUTE_ERROR_QUERY:
2252 {
2253 struct lttng_error_query *query;
2254 const struct lttng_credentials cmd_creds = {
2255 .uid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.uid),
2256 .gid = LTTNG_OPTIONAL_INIT_VALUE(cmd_ctx->creds.gid),
2257 };
2258 struct lttng_error_query_results *results = nullptr;
2259 size_t original_payload_size;
2260 size_t payload_size;
2261
2262 setup_empty_lttng_msg(cmd_ctx);
2263
2264 original_payload_size = cmd_ctx->reply_payload.buffer.size;
2265
2266 ret = receive_lttng_error_query(cmd_ctx, *sock, sock_error, &query);
2267 if (ret != LTTNG_OK) {
2268 goto error;
2269 }
2270
2271 ret = cmd_execute_error_query(
2272 &cmd_creds, query, &results, the_notification_thread_handle);
2273 lttng_error_query_destroy(query);
2274 if (ret != LTTNG_OK) {
2275 goto error;
2276 }
2277
2278 LTTNG_ASSERT(results);
2279 ret = lttng_error_query_results_serialize(results, &cmd_ctx->reply_payload);
2280 lttng_error_query_results_destroy(results);
2281 if (ret) {
2282 ERR("Failed to serialize error query result set in reply to `execute error query` command");
2283 ret = LTTNG_ERR_NOMEM;
2284 goto error;
2285 }
2286
2287 payload_size = cmd_ctx->reply_payload.buffer.size - original_payload_size;
2288
2289 update_lttng_msg(cmd_ctx, 0, payload_size);
2290
2291 ret = LTTNG_OK;
2292
2293 break;
2294 }
2295 default:
2296 ret = LTTNG_ERR_UND;
2297 break;
2298 }
2299
2300 error:
2301 if (cmd_ctx->reply_payload.buffer.size == 0) {
2302 DBG("Missing llm header, creating one.");
2303 setup_lttng_msg_no_cmd_header(cmd_ctx, nullptr, 0);
2304 }
2305
2306 command_ctx_set_status_code(*cmd_ctx, static_cast<lttng_error_code>(ret));
2307 LTTNG_ASSERT(!rcu_read_ongoing());
2308 return ret;
2309 }
2310
2311 static int create_client_sock()
2312 {
2313 int ret, client_sock;
2314
2315 /* Create client tool unix socket */
2316 client_sock = lttcomm_create_unix_sock(the_config.client_unix_sock_path.value);
2317 if (client_sock < 0) {
2318 ERR("Create unix sock failed: %s", the_config.client_unix_sock_path.value);
2319 ret = -1;
2320 goto end;
2321 }
2322
2323 /* Set the cloexec flag */
2324 ret = utils_set_fd_cloexec(client_sock);
2325 if (ret < 0) {
2326 ERR("Unable to set CLOEXEC flag to the client Unix socket (fd: %d). "
2327 "Continuing but note that the consumer daemon will have a "
2328 "reference to this socket on exec()",
2329 client_sock);
2330 }
2331
2332 /* File permission MUST be 660 */
2333 ret = chmod(the_config.client_unix_sock_path.value, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
2334 if (ret < 0) {
2335 ERR("Set file permissions failed: %s", the_config.client_unix_sock_path.value);
2336 PERROR("chmod");
2337 (void) lttcomm_close_unix_sock(client_sock);
2338 ret = -1;
2339 goto end;
2340 }
2341 DBG("Created client socket (fd = %i)", client_sock);
2342 ret = client_sock;
2343 end:
2344 return ret;
2345 }
2346
2347 static void cleanup_client_thread(void *data)
2348 {
2349 struct lttng_pipe *quit_pipe = (lttng_pipe *) data;
2350
2351 lttng_pipe_destroy(quit_pipe);
2352 }
2353
2354 static void thread_init_cleanup(void *data __attribute__((unused)))
2355 {
2356 set_thread_status(false);
2357 }
2358
2359 // Helper function to log the source_location if the exception is derived from lttng::runtime_error
2360 template <typename ExceptionType>
2361 typename std::enable_if<std::is_base_of<lttng::runtime_error, ExceptionType>::value,
2362 std::string>::type
2363 formatted_source_location(const ExceptionType& ex)
2364 {
2365 return fmt::format("{}", ex.source_location);
2366 }
2367
2368 template <typename ExceptionType>
2369 typename std::enable_if<!std::is_base_of<lttng::runtime_error, ExceptionType>::value,
2370 std::string>::type
2371 formatted_source_location(const ExceptionType&)
2372 {
2373 return "";
2374 }
2375
2376 template <class ExceptionType>
2377 static void log_nested_exceptions(const ExceptionType& ex, unsigned int level = 0)
2378 {
2379 const auto location = formatted_source_location(ex);
2380
2381 if (level == 0) {
2382 if (location.size()) {
2383 WARN_FMT("Client request failed: {}, location='{}'", ex.what(), location);
2384 } else {
2385 WARN_FMT("Client request failed: {}", ex.what());
2386 }
2387 } else {
2388 if (location.size()) {
2389 WARN_FMT("\t{}, location='{}'", ex.what(), location);
2390 } else {
2391 WARN_FMT("\t{}", ex.what());
2392 }
2393 }
2394
2395 try {
2396 std::rethrow_if_nested(ex);
2397 } catch (const lttng::runtime_error& nested_ex) {
2398 log_nested_exceptions(nested_ex, level + 1);
2399 } catch (const std::exception& nested_ex) {
2400 log_nested_exceptions(nested_ex, level + 1);
2401 }
2402 }
2403
2404 /*
2405 * This thread manage all clients request using the unix client socket for
2406 * communication.
2407 */
2408 static void *thread_manage_clients(void *data)
2409 {
2410 int sock = -1, ret, i, err = -1;
2411 int sock_error;
2412 uint32_t nb_fd;
2413 struct lttng_poll_event events;
2414 const int client_sock = thread_state.client_sock;
2415 struct lttng_pipe *quit_pipe = (lttng_pipe *) data;
2416 const int thread_quit_pipe_fd = lttng_pipe_get_readfd(quit_pipe);
2417 struct command_ctx cmd_ctx = {};
2418
2419 DBG("[thread] Manage client started");
2420
2421 lttng_payload_init(&cmd_ctx.reply_payload);
2422
2423 is_root = (getuid() == 0);
2424
2425 pthread_cleanup_push(thread_init_cleanup, nullptr);
2426
2427 rcu_register_thread();
2428
2429 health_register(the_health_sessiond, HEALTH_SESSIOND_TYPE_CMD);
2430
2431 health_code_update();
2432
2433 ret = lttcomm_listen_unix_sock(client_sock);
2434 if (ret < 0) {
2435 goto error_listen;
2436 }
2437
2438 /*
2439 * Pass 2 as size here for the thread quit pipe and client_sock. Nothing
2440 * more will be added to this poll set.
2441 */
2442 ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
2443 if (ret < 0) {
2444 goto error_create_poll;
2445 }
2446
2447 /* Add the application registration socket */
2448 ret = lttng_poll_add(&events, client_sock, LPOLLIN | LPOLLPRI);
2449 if (ret < 0) {
2450 goto error;
2451 }
2452
2453 /* Add thread quit pipe */
2454 ret = lttng_poll_add(&events, thread_quit_pipe_fd, LPOLLIN);
2455 if (ret < 0) {
2456 goto error;
2457 }
2458
2459 /* Set state as running. */
2460 set_thread_status(true);
2461 pthread_cleanup_pop(0);
2462
2463 /* This testpoint is after we signal readiness to the parent. */
2464 if (testpoint(sessiond_thread_manage_clients)) {
2465 goto error;
2466 }
2467
2468 if (testpoint(sessiond_thread_manage_clients_before_loop)) {
2469 goto error;
2470 }
2471
2472 health_code_update();
2473
2474 while (true) {
2475 const struct cmd_completion_handler *cmd_completion_handler;
2476
2477 cmd_ctx.creds.uid = UINT32_MAX;
2478 cmd_ctx.creds.gid = UINT32_MAX;
2479 cmd_ctx.creds.pid = 0;
2480 lttng_payload_clear(&cmd_ctx.reply_payload);
2481 cmd_ctx.lttng_msg_size = 0;
2482
2483 DBG("Accepting client command ...");
2484
2485 /* Inifinite blocking call, waiting for transmission */
2486 restart:
2487 health_poll_entry();
2488 ret = lttng_poll_wait(&events, -1);
2489 health_poll_exit();
2490 if (ret < 0) {
2491 /*
2492 * Restart interrupted system call.
2493 */
2494 if (errno == EINTR) {
2495 goto restart;
2496 }
2497 goto error;
2498 }
2499
2500 nb_fd = ret;
2501
2502 for (i = 0; i < nb_fd; i++) {
2503 /* Fetch once the poll data. */
2504 const auto revents = LTTNG_POLL_GETEV(&events, i);
2505 const auto pollfd = LTTNG_POLL_GETFD(&events, i);
2506
2507 health_code_update();
2508
2509 /* Activity on thread quit pipe, exiting. */
2510 if (pollfd == thread_quit_pipe_fd) {
2511 DBG("Activity on thread quit pipe");
2512 err = 0;
2513 goto exit;
2514 }
2515
2516 /* Event on the registration socket */
2517 if (revents & LPOLLIN) {
2518 continue;
2519 } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
2520 ERR("Client socket poll error");
2521 goto error;
2522 } else {
2523 ERR("Unexpected poll events %u for sock %d", revents, pollfd);
2524 goto error;
2525 }
2526 }
2527
2528 DBG("Wait for client response");
2529
2530 health_code_update();
2531
2532 sock = lttcomm_accept_unix_sock(client_sock);
2533 if (sock < 0) {
2534 goto error;
2535 }
2536
2537 /*
2538 * Set the CLOEXEC flag. Return code is useless because either way, the
2539 * show must go on.
2540 */
2541 (void) utils_set_fd_cloexec(sock);
2542
2543 /* Set socket option for credentials retrieval */
2544 ret = lttcomm_setsockopt_creds_unix_sock(sock);
2545 if (ret < 0) {
2546 goto error;
2547 }
2548
2549 health_code_update();
2550
2551 /*
2552 * Data is received from the lttng client. The struct
2553 * lttcomm_session_msg (lsm) contains the command and data request of
2554 * the client.
2555 */
2556 DBG("Receiving data from client ...");
2557 ret = lttcomm_recv_creds_unix_sock(
2558 sock, &cmd_ctx.lsm, sizeof(struct lttcomm_session_msg), &cmd_ctx.creds);
2559 if (ret != sizeof(struct lttcomm_session_msg)) {
2560 DBG("Incomplete recv() from client... continuing");
2561 ret = close(sock);
2562 if (ret) {
2563 PERROR("close");
2564 }
2565 sock = -1;
2566 continue;
2567 }
2568
2569 health_code_update();
2570
2571 // TODO: Validate cmd_ctx including sanity check for
2572 // security purpose.
2573
2574 rcu_thread_online();
2575 /*
2576 * This function dispatch the work to the kernel or userspace tracer
2577 * libs and fill the lttcomm_lttng_msg data structure of all the needed
2578 * informations for the client. The command context struct contains
2579 * everything this function may needs.
2580 */
2581 try {
2582 ret = process_client_msg(&cmd_ctx, &sock, &sock_error);
2583 rcu_thread_offline();
2584 } catch (const std::bad_alloc& ex) {
2585 log_nested_exceptions(ex);
2586 ret = LTTNG_ERR_NOMEM;
2587 } catch (const lttng::ctl::error& ex) {
2588 log_nested_exceptions(ex);
2589 ret = ex.code();
2590 } catch (const lttng::invalid_argument_error& ex) {
2591 log_nested_exceptions(ex);
2592 ret = LTTNG_ERR_INVALID;
2593 } catch (const lttng::sessiond::exceptions::session_not_found_error& ex) {
2594 log_nested_exceptions(ex);
2595 ret = LTTNG_ERR_SESS_NOT_FOUND;
2596 } catch (const lttng::runtime_error& ex) {
2597 log_nested_exceptions(ex);
2598 ret = LTTNG_ERR_UNK;
2599 } catch (const std::exception& ex) {
2600 log_nested_exceptions(ex);
2601 ret = LTTNG_ERR_UNK;
2602 }
2603
2604 if (ret < LTTNG_OK || ret >= LTTNG_ERR_NR) {
2605 WARN("Command returned an invalid status code, returning unknown error: "
2606 "command type = %s (%d), ret = %d",
2607 lttcomm_sessiond_command_str(
2608 (lttcomm_sessiond_command) cmd_ctx.lsm.cmd_type),
2609 cmd_ctx.lsm.cmd_type,
2610 ret);
2611 ret = LTTNG_ERR_UNK;
2612 }
2613
2614 if (ret != LTTNG_OK) {
2615 /*
2616 * Reset the payload contents as the command may have left them in an
2617 * inconsistent state.
2618 */
2619 setup_empty_lttng_msg(&cmd_ctx);
2620 }
2621
2622 command_ctx_set_status_code(cmd_ctx, static_cast<lttng_error_code>(ret));
2623
2624 cmd_completion_handler = cmd_pop_completion_handler();
2625 if (cmd_completion_handler) {
2626 enum lttng_error_code completion_code;
2627
2628 completion_code = cmd_completion_handler->run(cmd_completion_handler->data);
2629 if (completion_code != LTTNG_OK) {
2630 continue;
2631 }
2632 }
2633
2634 health_code_update();
2635
2636 if (sock >= 0) {
2637 struct lttng_payload_view view =
2638 lttng_payload_view_from_payload(&cmd_ctx.reply_payload, 0, -1);
2639 struct lttcomm_lttng_msg *llm =
2640 (typeof(llm)) cmd_ctx.reply_payload.buffer.data;
2641
2642 LTTNG_ASSERT(cmd_ctx.reply_payload.buffer.size >= sizeof(*llm));
2643 LTTNG_ASSERT(cmd_ctx.lttng_msg_size == cmd_ctx.reply_payload.buffer.size);
2644
2645 llm->fd_count = lttng_payload_view_get_fd_handle_count(&view);
2646
2647 DBG("Sending response (size: %d, retcode: %s (%d))",
2648 cmd_ctx.lttng_msg_size,
2649 lttng_strerror(-llm->ret_code),
2650 llm->ret_code);
2651 ret = send_unix_sock(sock, &view);
2652 if (ret < 0) {
2653 ERR("Failed to send data back to client");
2654 }
2655
2656 /* End of transmission */
2657 ret = close(sock);
2658 if (ret) {
2659 PERROR("close");
2660 }
2661 }
2662 sock = -1;
2663
2664 health_code_update();
2665 }
2666
2667 exit:
2668 error:
2669 if (sock >= 0) {
2670 ret = close(sock);
2671 if (ret) {
2672 PERROR("close");
2673 }
2674 }
2675
2676 lttng_poll_clean(&events);
2677
2678 error_listen:
2679 error_create_poll:
2680 unlink(the_config.client_unix_sock_path.value);
2681 ret = close(client_sock);
2682 if (ret) {
2683 PERROR("close");
2684 }
2685
2686 if (err) {
2687 health_error();
2688 ERR("Health error occurred in %s", __func__);
2689 }
2690
2691 health_unregister(the_health_sessiond);
2692
2693 DBG("Client thread dying");
2694 lttng_payload_reset(&cmd_ctx.reply_payload);
2695 rcu_unregister_thread();
2696 return nullptr;
2697 }
2698
2699 static bool shutdown_client_thread(void *thread_data)
2700 {
2701 struct lttng_pipe *client_quit_pipe = (lttng_pipe *) thread_data;
2702 const int write_fd = lttng_pipe_get_writefd(client_quit_pipe);
2703
2704 return notify_thread_pipe(write_fd) == 1;
2705 }
2706
2707 struct lttng_thread *launch_client_thread()
2708 {
2709 bool thread_running;
2710 struct lttng_pipe *client_quit_pipe;
2711 struct lttng_thread *thread = nullptr;
2712 int client_sock_fd = -1;
2713
2714 sem_init(&thread_state.ready, 0, 0);
2715 client_quit_pipe = lttng_pipe_open(FD_CLOEXEC);
2716 if (!client_quit_pipe) {
2717 goto error;
2718 }
2719
2720 client_sock_fd = create_client_sock();
2721 if (client_sock_fd < 0) {
2722 goto error;
2723 }
2724
2725 thread_state.client_sock = client_sock_fd;
2726 thread = lttng_thread_create("Client management",
2727 thread_manage_clients,
2728 shutdown_client_thread,
2729 cleanup_client_thread,
2730 client_quit_pipe);
2731 if (!thread) {
2732 goto error;
2733 }
2734 /* The client thread now owns the client sock fd and the quit pipe. */
2735 client_sock_fd = -1;
2736 client_quit_pipe = nullptr;
2737
2738 /*
2739 * This thread is part of the threads that need to be fully
2740 * initialized before the session daemon is marked as "ready".
2741 */
2742 thread_running = wait_thread_status();
2743 if (!thread_running) {
2744 goto error;
2745 }
2746 return thread;
2747 error:
2748 if (client_sock_fd >= 0) {
2749 if (close(client_sock_fd)) {
2750 PERROR("Failed to close client socket");
2751 }
2752 }
2753 lttng_thread_put(thread);
2754 cleanup_client_thread(client_quit_pipe);
2755 return nullptr;
2756 }
LTTng 2.0 tools and control repository
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