Commit | Line | Data |
---|---|---|
4d076222 | 1 | /* |
ab5be9fa | 2 | * Copyright (C) 2013 David Goulet <dgoulet@efficios.com> |
4d076222 | 3 | * |
ab5be9fa | 4 | * SPDX-License-Identifier: GPL-2.0-only |
4d076222 | 5 | * |
4d076222 DG |
6 | */ |
7 | ||
6c1c0768 | 8 | #define _LGPL_SOURCE |
4d076222 DG |
9 | #include <assert.h> |
10 | ||
11 | #include <common/common.h> | |
12 | #include <common/sessiond-comm/sessiond-comm.h> | |
13 | #include <common/uri.h> | |
14 | #include <common/utils.h> | |
15 | ||
f263b7fd JD |
16 | #include <common/compat/endian.h> |
17 | ||
4d076222 | 18 | #include "fd-limit.h" |
022d91ba | 19 | #include "agent-thread.h" |
6a4e4039 | 20 | #include "agent.h" |
4d076222 | 21 | #include "lttng-sessiond.h" |
f20baf8e DG |
22 | #include "session.h" |
23 | #include "utils.h" | |
8a7e4590 | 24 | #include "thread.h" |
4d076222 | 25 | |
c78d8e86 JG |
26 | struct thread_notifiers { |
27 | struct lttng_pipe *quit_pipe; | |
28 | sem_t ready; | |
29 | }; | |
30 | ||
f28f9e44 JG |
31 | static int agent_tracing_enabled = -1; |
32 | ||
4d076222 DG |
33 | /* |
34 | * Note that there is not port here. It's set after this URI is parsed so we | |
35 | * can let the user define a custom one. However, localhost is ALWAYS the | |
36 | * default listening address. | |
37 | */ | |
fa91dc52 MD |
38 | static const char *default_reg_uri = |
39 | "tcp://" DEFAULT_NETWORK_VIEWER_BIND_ADDRESS; | |
4d076222 | 40 | |
f20baf8e | 41 | /* |
022d91ba | 42 | * Update agent application using the given socket. This is done just after |
f20baf8e DG |
43 | * registration was successful. |
44 | * | |
45 | * This is a quite heavy call in terms of locking since the session list lock | |
46 | * AND session lock are acquired. | |
47 | */ | |
fefd409b | 48 | static void update_agent_app(struct agent_app *app) |
f20baf8e DG |
49 | { |
50 | struct ltt_session *session, *stmp; | |
51 | struct ltt_session_list *list; | |
52 | ||
53 | list = session_get_list(); | |
54 | assert(list); | |
55 | ||
56 | session_lock_list(); | |
57 | cds_list_for_each_entry_safe(session, stmp, &list->head, list) { | |
e32d7f27 JG |
58 | if (!session_get(session)) { |
59 | continue; | |
60 | } | |
61 | ||
f20baf8e DG |
62 | session_lock(session); |
63 | if (session->ust_session) { | |
fefd409b DG |
64 | struct agent *agt; |
65 | ||
4da703ad | 66 | rcu_read_lock(); |
fefd409b DG |
67 | agt = trace_ust_find_agent(session->ust_session, app->domain); |
68 | if (agt) { | |
69 | agent_update(agt, app->sock->fd); | |
70 | } | |
4da703ad | 71 | rcu_read_unlock(); |
f20baf8e DG |
72 | } |
73 | session_unlock(session); | |
e32d7f27 | 74 | session_put(session); |
f20baf8e DG |
75 | } |
76 | session_unlock_list(); | |
77 | } | |
78 | ||
4d076222 DG |
79 | /* |
80 | * Create and init socket from uri. | |
81 | */ | |
82 | static struct lttcomm_sock *init_tcp_socket(void) | |
83 | { | |
84 | int ret; | |
85 | struct lttng_uri *uri = NULL; | |
86 | struct lttcomm_sock *sock = NULL; | |
2288467f JG |
87 | unsigned int port; |
88 | bool bind_succeeded = false; | |
4d076222 DG |
89 | |
90 | /* | |
91 | * This should never fail since the URI is hardcoded and the port is set | |
92 | * before this thread is launched. | |
93 | */ | |
94 | ret = uri_parse(default_reg_uri, &uri); | |
95 | assert(ret); | |
2288467f JG |
96 | assert(config.agent_tcp_port.begin > 0); |
97 | uri->port = config.agent_tcp_port.begin; | |
4d076222 DG |
98 | |
99 | sock = lttcomm_alloc_sock_from_uri(uri); | |
100 | uri_free(uri); | |
101 | if (sock == NULL) { | |
022d91ba | 102 | ERR("[agent-thread] agent allocating TCP socket"); |
4d076222 DG |
103 | goto error; |
104 | } | |
105 | ||
106 | ret = lttcomm_create_sock(sock); | |
107 | if (ret < 0) { | |
108 | goto error; | |
109 | } | |
110 | ||
2288467f JG |
111 | for (port = config.agent_tcp_port.begin; |
112 | port <= config.agent_tcp_port.end; port++) { | |
113 | ret = lttcomm_sock_set_port(sock, (uint16_t) port); | |
114 | if (ret) { | |
115 | ERR("[agent-thread] Failed to set port %u on socket", | |
116 | port); | |
117 | goto error; | |
118 | } | |
119 | DBG3("[agent-thread] Trying to bind on port %u", port); | |
120 | ret = sock->ops->bind(sock); | |
121 | if (!ret) { | |
122 | bind_succeeded = true; | |
123 | break; | |
124 | } | |
125 | ||
126 | if (errno == EADDRINUSE) { | |
127 | DBG("Failed to bind to port %u since it is already in use", | |
128 | port); | |
129 | } else { | |
130 | PERROR("Failed to bind to port %u", port); | |
131 | goto error; | |
132 | } | |
133 | } | |
134 | ||
135 | if (!bind_succeeded) { | |
136 | if (config.agent_tcp_port.begin == config.agent_tcp_port.end) { | |
137 | WARN("Another process is already using the agent port %i. " | |
138 | "Agent support will be deactivated.", | |
139 | config.agent_tcp_port.begin); | |
140 | goto error; | |
141 | } else { | |
142 | WARN("All ports in the range [%i, %i] are already in use. " | |
143 | "Agent support will be deactivated.", | |
144 | config.agent_tcp_port.begin, | |
145 | config.agent_tcp_port.end); | |
146 | goto error; | |
147 | } | |
4d076222 DG |
148 | } |
149 | ||
150 | ret = sock->ops->listen(sock, -1); | |
151 | if (ret < 0) { | |
152 | goto error; | |
153 | } | |
154 | ||
022d91ba | 155 | DBG("[agent-thread] Listening on TCP port %u and socket %d", |
2288467f | 156 | port, sock->fd); |
4d076222 DG |
157 | |
158 | return sock; | |
159 | ||
160 | error: | |
161 | if (sock) { | |
162 | lttcomm_destroy_sock(sock); | |
163 | } | |
164 | return NULL; | |
165 | } | |
166 | ||
167 | /* | |
168 | * Close and destroy the given TCP socket. | |
169 | */ | |
170 | static void destroy_tcp_socket(struct lttcomm_sock *sock) | |
171 | { | |
2288467f JG |
172 | int ret; |
173 | uint16_t port; | |
174 | ||
4d076222 DG |
175 | assert(sock); |
176 | ||
2288467f JG |
177 | ret = lttcomm_sock_get_port(sock, &port); |
178 | if (ret) { | |
179 | ERR("[agent-thread] Failed to get port of agent TCP socket"); | |
180 | port = 0; | |
181 | } | |
182 | ||
183 | DBG3("[agent-thread] Destroy TCP socket on port %" PRIu16, | |
184 | port); | |
4d076222 DG |
185 | |
186 | /* This will return gracefully if fd is invalid. */ | |
187 | sock->ops->close(sock); | |
188 | lttcomm_destroy_sock(sock); | |
189 | } | |
190 | ||
f20baf8e | 191 | /* |
022d91ba DG |
192 | * Handle a new agent registration using the reg socket. After that, a new |
193 | * agent application is added to the global hash table and attach to an UST app | |
1b500e7a | 194 | * object. If r_app is not NULL, the created app is set to the pointer. |
f20baf8e DG |
195 | * |
196 | * Return the new FD created upon accept() on success or else a negative errno | |
197 | * value. | |
198 | */ | |
1b500e7a | 199 | static int handle_registration(struct lttcomm_sock *reg_sock, |
022d91ba | 200 | struct agent_app **r_app) |
f20baf8e DG |
201 | { |
202 | int ret; | |
203 | pid_t pid; | |
9474416f | 204 | uint32_t major_version, minor_version; |
f20baf8e | 205 | ssize_t size; |
fefd409b | 206 | enum lttng_domain_type domain; |
022d91ba DG |
207 | struct agent_app *app; |
208 | struct agent_register_msg msg; | |
f20baf8e DG |
209 | struct lttcomm_sock *new_sock; |
210 | ||
211 | assert(reg_sock); | |
212 | ||
213 | new_sock = reg_sock->ops->accept(reg_sock); | |
214 | if (!new_sock) { | |
215 | ret = -ENOTCONN; | |
216 | goto error; | |
217 | } | |
218 | ||
219 | size = new_sock->ops->recvmsg(new_sock, &msg, sizeof(msg), 0); | |
220 | if (size < sizeof(msg)) { | |
79865500 | 221 | ret = -EINVAL; |
f20baf8e DG |
222 | goto error_socket; |
223 | } | |
fefd409b | 224 | domain = be32toh(msg.domain); |
f20baf8e | 225 | pid = be32toh(msg.pid); |
9474416f DG |
226 | major_version = be32toh(msg.major_version); |
227 | minor_version = be32toh(msg.minor_version); | |
228 | ||
229 | /* Test communication protocol version of the registring agent. */ | |
230 | if (major_version != AGENT_MAJOR_VERSION) { | |
231 | ret = -EINVAL; | |
232 | goto error_socket; | |
233 | } | |
234 | if (minor_version != AGENT_MINOR_VERSION) { | |
235 | ret = -EINVAL; | |
236 | goto error_socket; | |
237 | } | |
f20baf8e | 238 | |
fefd409b DG |
239 | DBG2("[agent-thread] New registration for pid %d domain %d on socket %d", |
240 | pid, domain, new_sock->fd); | |
f20baf8e | 241 | |
fefd409b | 242 | app = agent_create_app(pid, domain, new_sock); |
f20baf8e DG |
243 | if (!app) { |
244 | ret = -ENOMEM; | |
245 | goto error_socket; | |
246 | } | |
247 | ||
248 | /* | |
249 | * Add before assigning the socket value to the UST app so it can be found | |
250 | * concurrently. | |
251 | */ | |
022d91ba | 252 | agent_add_app(app); |
f20baf8e DG |
253 | |
254 | /* | |
022d91ba DG |
255 | * We don't need to attach the agent app to the app. If we ever do so, we |
256 | * should consider both registration order of agent before app and app | |
257 | * before agent. | |
f20baf8e | 258 | */ |
f20baf8e | 259 | |
1b500e7a DG |
260 | if (r_app) { |
261 | *r_app = app; | |
262 | } | |
263 | ||
f20baf8e DG |
264 | return new_sock->fd; |
265 | ||
266 | error_socket: | |
267 | new_sock->ops->close(new_sock); | |
268 | lttcomm_destroy_sock(new_sock); | |
269 | error: | |
270 | return ret; | |
271 | } | |
272 | ||
f28f9e44 JG |
273 | bool agent_tracing_is_enabled(void) |
274 | { | |
275 | int enabled; | |
276 | ||
277 | enabled = uatomic_read(&agent_tracing_enabled); | |
278 | assert(enabled != -1); | |
279 | return enabled == 1; | |
280 | } | |
281 | ||
2288467f JG |
282 | /* |
283 | * Write agent TCP port using the rundir. | |
284 | */ | |
285 | static int write_agent_port(uint16_t port) | |
286 | { | |
287 | return utils_create_pid_file((pid_t) port, | |
288 | config.agent_port_file_path.value); | |
289 | } | |
290 | ||
c78d8e86 JG |
291 | static |
292 | void mark_thread_as_ready(struct thread_notifiers *notifiers) | |
293 | { | |
294 | DBG("Marking agent management thread as ready"); | |
295 | sem_post(¬ifiers->ready); | |
296 | } | |
297 | ||
298 | static | |
299 | void wait_until_thread_is_ready(struct thread_notifiers *notifiers) | |
300 | { | |
301 | DBG("Waiting for agent management thread to be ready"); | |
302 | sem_wait(¬ifiers->ready); | |
303 | DBG("Agent management thread is ready"); | |
304 | } | |
305 | ||
4d076222 DG |
306 | /* |
307 | * This thread manage application notify communication. | |
308 | */ | |
8a7e4590 | 309 | static void *thread_agent_management(void *data) |
4d076222 DG |
310 | { |
311 | int i, ret, pollfd; | |
312 | uint32_t revents, nb_fd; | |
313 | struct lttng_poll_event events; | |
314 | struct lttcomm_sock *reg_sock; | |
c78d8e86 JG |
315 | struct thread_notifiers *notifiers = data; |
316 | const int quit_pipe_read_fd = lttng_pipe_get_readfd( | |
317 | notifiers->quit_pipe); | |
4d076222 | 318 | |
022d91ba | 319 | DBG("[agent-thread] Manage agent application registration."); |
4d076222 DG |
320 | |
321 | rcu_register_thread(); | |
322 | rcu_thread_online(); | |
323 | ||
022d91ba DG |
324 | /* Agent initialization call MUST be called before starting the thread. */ |
325 | assert(agent_apps_ht_by_sock); | |
f20baf8e | 326 | |
8a7e4590 JG |
327 | /* Create pollset with size 2, quit pipe and registration socket. */ |
328 | ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC); | |
4d076222 DG |
329 | if (ret < 0) { |
330 | goto error_poll_create; | |
331 | } | |
332 | ||
8a7e4590 JG |
333 | ret = lttng_poll_add(&events, quit_pipe_read_fd, |
334 | LPOLLIN | LPOLLERR); | |
335 | if (ret < 0) { | |
336 | goto error_tcp_socket; | |
337 | } | |
338 | ||
4d076222 | 339 | reg_sock = init_tcp_socket(); |
2288467f JG |
340 | if (reg_sock) { |
341 | uint16_t port; | |
342 | ||
343 | assert(lttcomm_sock_get_port(reg_sock, &port) == 0); | |
344 | ||
345 | ret = write_agent_port(port); | |
346 | if (ret) { | |
347 | ERR("[agent-thread] Failed to create agent port file: agent tracing will be unavailable"); | |
348 | /* Don't prevent the launch of the sessiond on error. */ | |
c78d8e86 | 349 | mark_thread_as_ready(notifiers); |
2288467f JG |
350 | goto error; |
351 | } | |
352 | } else { | |
353 | /* Don't prevent the launch of the sessiond on error. */ | |
c78d8e86 | 354 | mark_thread_as_ready(notifiers); |
2288467f JG |
355 | goto error_tcp_socket; |
356 | } | |
f28f9e44 JG |
357 | |
358 | /* | |
359 | * Signal that the agent thread is ready. The command thread | |
360 | * may start to query whether or not agent tracing is enabled. | |
361 | */ | |
2288467f | 362 | uatomic_set(&agent_tracing_enabled, 1); |
c78d8e86 | 363 | mark_thread_as_ready(notifiers); |
4d076222 | 364 | |
427392b4 | 365 | /* Add TCP socket to poll set. */ |
4d076222 DG |
366 | ret = lttng_poll_add(&events, reg_sock->fd, |
367 | LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP); | |
368 | if (ret < 0) { | |
369 | goto error; | |
370 | } | |
371 | ||
372 | while (1) { | |
546f19b5 | 373 | DBG3("[agent-thread] Manage agent polling"); |
4d076222 DG |
374 | |
375 | /* Inifinite blocking call, waiting for transmission */ | |
376 | restart: | |
377 | ret = lttng_poll_wait(&events, -1); | |
7fa2082e MD |
378 | DBG3("[agent-thread] Manage agent return from poll on %d fds", |
379 | LTTNG_POLL_GETNB(&events)); | |
4d076222 DG |
380 | if (ret < 0) { |
381 | /* | |
382 | * Restart interrupted system call. | |
383 | */ | |
384 | if (errno == EINTR) { | |
385 | goto restart; | |
386 | } | |
387 | goto error; | |
388 | } | |
389 | nb_fd = ret; | |
022d91ba | 390 | DBG3("[agent-thread] %d fd ready", nb_fd); |
4d076222 DG |
391 | |
392 | for (i = 0; i < nb_fd; i++) { | |
393 | /* Fetch once the poll data */ | |
394 | revents = LTTNG_POLL_GETEV(&events, i); | |
395 | pollfd = LTTNG_POLL_GETFD(&events, i); | |
396 | ||
397 | /* Thread quit pipe has been closed. Killing thread. */ | |
8a7e4590 | 398 | if (pollfd == quit_pipe_read_fd) { |
4d076222 DG |
399 | goto exit; |
400 | } | |
401 | ||
03e43155 | 402 | if (revents & LPOLLIN) { |
f20baf8e | 403 | int new_fd; |
022d91ba | 404 | struct agent_app *app = NULL; |
f20baf8e | 405 | |
f20baf8e | 406 | assert(pollfd == reg_sock->fd); |
1b500e7a | 407 | new_fd = handle_registration(reg_sock, &app); |
f20baf8e | 408 | if (new_fd < 0) { |
f20baf8e DG |
409 | continue; |
410 | } | |
1b500e7a DG |
411 | /* Should not have a NULL app on success. */ |
412 | assert(app); | |
f20baf8e | 413 | |
03e43155 MD |
414 | /* |
415 | * Since this is a command socket (write then read), | |
416 | * only add poll error event to only detect shutdown. | |
417 | */ | |
f20baf8e DG |
418 | ret = lttng_poll_add(&events, new_fd, |
419 | LPOLLERR | LPOLLHUP | LPOLLRDHUP); | |
420 | if (ret < 0) { | |
6a4e4039 | 421 | agent_destroy_app_by_sock(new_fd); |
f20baf8e DG |
422 | continue; |
423 | } | |
424 | ||
425 | /* Update newly registered app. */ | |
fefd409b | 426 | update_agent_app(app); |
1b500e7a DG |
427 | |
428 | /* On failure, the poll will detect it and clean it up. */ | |
03e43155 MD |
429 | ret = agent_send_registration_done(app); |
430 | if (ret < 0) { | |
431 | /* Removing from the poll set */ | |
432 | ret = lttng_poll_del(&events, new_fd); | |
433 | if (ret < 0) { | |
434 | goto error; | |
435 | } | |
436 | agent_destroy_app_by_sock(new_fd); | |
437 | continue; | |
438 | } | |
439 | } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) { | |
440 | /* Removing from the poll set */ | |
441 | ret = lttng_poll_del(&events, pollfd); | |
442 | if (ret < 0) { | |
443 | goto error; | |
444 | } | |
445 | agent_destroy_app_by_sock(pollfd); | |
4d076222 | 446 | } else { |
03e43155 MD |
447 | ERR("Unexpected poll events %u for sock %d", revents, pollfd); |
448 | goto error; | |
4d076222 DG |
449 | } |
450 | } | |
451 | } | |
452 | ||
453 | exit: | |
f20baf8e DG |
454 | /* Whatever happens, try to delete it and exit. */ |
455 | (void) lttng_poll_del(&events, reg_sock->fd); | |
4d076222 DG |
456 | error: |
457 | destroy_tcp_socket(reg_sock); | |
458 | error_tcp_socket: | |
459 | lttng_poll_clean(&events); | |
460 | error_poll_create: | |
2288467f | 461 | uatomic_set(&agent_tracing_enabled, 0); |
8a7e4590 | 462 | DBG("[agent-thread] Cleaning up and stopping."); |
4d076222 DG |
463 | rcu_thread_offline(); |
464 | rcu_unregister_thread(); | |
465 | return NULL; | |
466 | } | |
8a7e4590 JG |
467 | |
468 | static bool shutdown_agent_management_thread(void *data) | |
469 | { | |
c78d8e86 JG |
470 | struct thread_notifiers *notifiers = data; |
471 | const int write_fd = lttng_pipe_get_writefd(notifiers->quit_pipe); | |
8a7e4590 JG |
472 | |
473 | return notify_thread_pipe(write_fd) == 1; | |
474 | } | |
475 | ||
5b093681 JG |
476 | static void cleanup_agent_management_thread(void *data) |
477 | { | |
c78d8e86 | 478 | struct thread_notifiers *notifiers = data; |
5b093681 | 479 | |
c78d8e86 JG |
480 | lttng_pipe_destroy(notifiers->quit_pipe); |
481 | sem_destroy(¬ifiers->ready); | |
482 | free(notifiers); | |
5b093681 JG |
483 | } |
484 | ||
485 | bool launch_agent_management_thread(void) | |
8a7e4590 | 486 | { |
c78d8e86 | 487 | struct thread_notifiers *notifiers; |
8a7e4590 JG |
488 | struct lttng_thread *thread; |
489 | ||
c78d8e86 JG |
490 | notifiers = zmalloc(sizeof(*notifiers)); |
491 | if (!notifiers) { | |
21fa020e | 492 | goto error_alloc; |
c78d8e86 JG |
493 | } |
494 | ||
495 | sem_init(¬ifiers->ready, 0, 0); | |
496 | notifiers->quit_pipe = lttng_pipe_open(FD_CLOEXEC); | |
497 | if (!notifiers->quit_pipe) { | |
8a7e4590 JG |
498 | goto error; |
499 | } | |
500 | thread = lttng_thread_create("Agent management", | |
501 | thread_agent_management, | |
502 | shutdown_agent_management_thread, | |
5b093681 | 503 | cleanup_agent_management_thread, |
c78d8e86 | 504 | notifiers); |
8a7e4590 JG |
505 | if (!thread) { |
506 | goto error; | |
507 | } | |
c78d8e86 | 508 | wait_until_thread_is_ready(notifiers); |
8a7e4590 JG |
509 | lttng_thread_put(thread); |
510 | return true; | |
511 | error: | |
c78d8e86 | 512 | cleanup_agent_management_thread(notifiers); |
21fa020e | 513 | error_alloc: |
8a7e4590 JG |
514 | return false; |
515 | } |