Commit | Line | Data |
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4d076222 DG |
1 | /* |
2 | * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify it | |
5 | * under the terms of the GNU General Public License, version 2 only, as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
11 | * more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License along with | |
14 | * this program; if not, write to the Free Software Foundation, Inc., 51 | |
15 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
16 | */ | |
17 | ||
6c1c0768 | 18 | #define _LGPL_SOURCE |
4d076222 DG |
19 | #include <assert.h> |
20 | ||
21 | #include <common/common.h> | |
22 | #include <common/sessiond-comm/sessiond-comm.h> | |
23 | #include <common/uri.h> | |
24 | #include <common/utils.h> | |
25 | ||
f263b7fd JD |
26 | #include <common/compat/endian.h> |
27 | ||
4d076222 | 28 | #include "fd-limit.h" |
022d91ba | 29 | #include "agent-thread.h" |
6a4e4039 | 30 | #include "agent.h" |
4d076222 | 31 | #include "lttng-sessiond.h" |
f20baf8e DG |
32 | #include "session.h" |
33 | #include "utils.h" | |
7baf7871 | 34 | #include "thread.h" |
4d076222 | 35 | |
f28f9e44 JG |
36 | static int agent_tracing_enabled = -1; |
37 | ||
4d076222 DG |
38 | /* |
39 | * Note that there is not port here. It's set after this URI is parsed so we | |
40 | * can let the user define a custom one. However, localhost is ALWAYS the | |
41 | * default listening address. | |
42 | */ | |
fa91dc52 MD |
43 | static const char *default_reg_uri = |
44 | "tcp://" DEFAULT_NETWORK_VIEWER_BIND_ADDRESS; | |
4d076222 | 45 | |
f20baf8e | 46 | /* |
022d91ba | 47 | * Update agent application using the given socket. This is done just after |
f20baf8e DG |
48 | * registration was successful. |
49 | * | |
50 | * This is a quite heavy call in terms of locking since the session list lock | |
51 | * AND session lock are acquired. | |
52 | */ | |
fefd409b | 53 | static void update_agent_app(struct agent_app *app) |
f20baf8e DG |
54 | { |
55 | struct ltt_session *session, *stmp; | |
56 | struct ltt_session_list *list; | |
57 | ||
58 | list = session_get_list(); | |
59 | assert(list); | |
60 | ||
61 | session_lock_list(); | |
62 | cds_list_for_each_entry_safe(session, stmp, &list->head, list) { | |
48a86f68 JG |
63 | if (!session_get(session)) { |
64 | continue; | |
65 | } | |
66 | ||
f20baf8e DG |
67 | session_lock(session); |
68 | if (session->ust_session) { | |
fefd409b DG |
69 | struct agent *agt; |
70 | ||
4da703ad | 71 | rcu_read_lock(); |
fefd409b DG |
72 | agt = trace_ust_find_agent(session->ust_session, app->domain); |
73 | if (agt) { | |
74 | agent_update(agt, app->sock->fd); | |
75 | } | |
4da703ad | 76 | rcu_read_unlock(); |
f20baf8e DG |
77 | } |
78 | session_unlock(session); | |
48a86f68 | 79 | session_put(session); |
f20baf8e DG |
80 | } |
81 | session_unlock_list(); | |
82 | } | |
83 | ||
4d076222 DG |
84 | /* |
85 | * Create and init socket from uri. | |
86 | */ | |
87 | static struct lttcomm_sock *init_tcp_socket(void) | |
88 | { | |
89 | int ret; | |
90 | struct lttng_uri *uri = NULL; | |
91 | struct lttcomm_sock *sock = NULL; | |
2288467f JG |
92 | unsigned int port; |
93 | bool bind_succeeded = false; | |
4d076222 DG |
94 | |
95 | /* | |
96 | * This should never fail since the URI is hardcoded and the port is set | |
97 | * before this thread is launched. | |
98 | */ | |
99 | ret = uri_parse(default_reg_uri, &uri); | |
100 | assert(ret); | |
2288467f JG |
101 | assert(config.agent_tcp_port.begin > 0); |
102 | uri->port = config.agent_tcp_port.begin; | |
4d076222 DG |
103 | |
104 | sock = lttcomm_alloc_sock_from_uri(uri); | |
105 | uri_free(uri); | |
106 | if (sock == NULL) { | |
022d91ba | 107 | ERR("[agent-thread] agent allocating TCP socket"); |
4d076222 DG |
108 | goto error; |
109 | } | |
110 | ||
111 | ret = lttcomm_create_sock(sock); | |
112 | if (ret < 0) { | |
113 | goto error; | |
114 | } | |
115 | ||
2288467f JG |
116 | for (port = config.agent_tcp_port.begin; |
117 | port <= config.agent_tcp_port.end; port++) { | |
118 | ret = lttcomm_sock_set_port(sock, (uint16_t) port); | |
119 | if (ret) { | |
120 | ERR("[agent-thread] Failed to set port %u on socket", | |
121 | port); | |
122 | goto error; | |
123 | } | |
124 | DBG3("[agent-thread] Trying to bind on port %u", port); | |
125 | ret = sock->ops->bind(sock); | |
126 | if (!ret) { | |
127 | bind_succeeded = true; | |
128 | break; | |
129 | } | |
130 | ||
131 | if (errno == EADDRINUSE) { | |
132 | DBG("Failed to bind to port %u since it is already in use", | |
133 | port); | |
134 | } else { | |
135 | PERROR("Failed to bind to port %u", port); | |
136 | goto error; | |
137 | } | |
138 | } | |
139 | ||
140 | if (!bind_succeeded) { | |
141 | if (config.agent_tcp_port.begin == config.agent_tcp_port.end) { | |
142 | WARN("Another process is already using the agent port %i. " | |
143 | "Agent support will be deactivated.", | |
144 | config.agent_tcp_port.begin); | |
145 | goto error; | |
146 | } else { | |
147 | WARN("All ports in the range [%i, %i] are already in use. " | |
148 | "Agent support will be deactivated.", | |
149 | config.agent_tcp_port.begin, | |
150 | config.agent_tcp_port.end); | |
151 | goto error; | |
152 | } | |
4d076222 DG |
153 | } |
154 | ||
155 | ret = sock->ops->listen(sock, -1); | |
156 | if (ret < 0) { | |
157 | goto error; | |
158 | } | |
159 | ||
022d91ba | 160 | DBG("[agent-thread] Listening on TCP port %u and socket %d", |
2288467f | 161 | port, sock->fd); |
4d076222 DG |
162 | |
163 | return sock; | |
164 | ||
165 | error: | |
166 | if (sock) { | |
167 | lttcomm_destroy_sock(sock); | |
168 | } | |
169 | return NULL; | |
170 | } | |
171 | ||
172 | /* | |
173 | * Close and destroy the given TCP socket. | |
174 | */ | |
175 | static void destroy_tcp_socket(struct lttcomm_sock *sock) | |
176 | { | |
2288467f JG |
177 | int ret; |
178 | uint16_t port; | |
179 | ||
4d076222 DG |
180 | assert(sock); |
181 | ||
2288467f JG |
182 | ret = lttcomm_sock_get_port(sock, &port); |
183 | if (ret) { | |
184 | ERR("[agent-thread] Failed to get port of agent TCP socket"); | |
185 | port = 0; | |
186 | } | |
187 | ||
188 | DBG3("[agent-thread] Destroy TCP socket on port %" PRIu16, | |
189 | port); | |
4d076222 DG |
190 | |
191 | /* This will return gracefully if fd is invalid. */ | |
192 | sock->ops->close(sock); | |
193 | lttcomm_destroy_sock(sock); | |
194 | } | |
195 | ||
f20baf8e | 196 | /* |
022d91ba DG |
197 | * Handle a new agent registration using the reg socket. After that, a new |
198 | * agent application is added to the global hash table and attach to an UST app | |
1b500e7a | 199 | * object. If r_app is not NULL, the created app is set to the pointer. |
f20baf8e DG |
200 | * |
201 | * Return the new FD created upon accept() on success or else a negative errno | |
202 | * value. | |
203 | */ | |
1b500e7a | 204 | static int handle_registration(struct lttcomm_sock *reg_sock, |
022d91ba | 205 | struct agent_app **r_app) |
f20baf8e DG |
206 | { |
207 | int ret; | |
208 | pid_t pid; | |
9474416f | 209 | uint32_t major_version, minor_version; |
f20baf8e | 210 | ssize_t size; |
fefd409b | 211 | enum lttng_domain_type domain; |
022d91ba DG |
212 | struct agent_app *app; |
213 | struct agent_register_msg msg; | |
f20baf8e DG |
214 | struct lttcomm_sock *new_sock; |
215 | ||
216 | assert(reg_sock); | |
217 | ||
218 | new_sock = reg_sock->ops->accept(reg_sock); | |
219 | if (!new_sock) { | |
220 | ret = -ENOTCONN; | |
221 | goto error; | |
222 | } | |
223 | ||
224 | size = new_sock->ops->recvmsg(new_sock, &msg, sizeof(msg), 0); | |
225 | if (size < sizeof(msg)) { | |
79865500 | 226 | ret = -EINVAL; |
f20baf8e DG |
227 | goto error_socket; |
228 | } | |
fefd409b | 229 | domain = be32toh(msg.domain); |
f20baf8e | 230 | pid = be32toh(msg.pid); |
9474416f DG |
231 | major_version = be32toh(msg.major_version); |
232 | minor_version = be32toh(msg.minor_version); | |
233 | ||
234 | /* Test communication protocol version of the registring agent. */ | |
235 | if (major_version != AGENT_MAJOR_VERSION) { | |
236 | ret = -EINVAL; | |
237 | goto error_socket; | |
238 | } | |
239 | if (minor_version != AGENT_MINOR_VERSION) { | |
240 | ret = -EINVAL; | |
241 | goto error_socket; | |
242 | } | |
f20baf8e | 243 | |
fefd409b DG |
244 | DBG2("[agent-thread] New registration for pid %d domain %d on socket %d", |
245 | pid, domain, new_sock->fd); | |
f20baf8e | 246 | |
fefd409b | 247 | app = agent_create_app(pid, domain, new_sock); |
f20baf8e DG |
248 | if (!app) { |
249 | ret = -ENOMEM; | |
250 | goto error_socket; | |
251 | } | |
252 | ||
253 | /* | |
254 | * Add before assigning the socket value to the UST app so it can be found | |
255 | * concurrently. | |
256 | */ | |
022d91ba | 257 | agent_add_app(app); |
f20baf8e DG |
258 | |
259 | /* | |
022d91ba DG |
260 | * We don't need to attach the agent app to the app. If we ever do so, we |
261 | * should consider both registration order of agent before app and app | |
262 | * before agent. | |
f20baf8e | 263 | */ |
f20baf8e | 264 | |
1b500e7a DG |
265 | if (r_app) { |
266 | *r_app = app; | |
267 | } | |
268 | ||
f20baf8e DG |
269 | return new_sock->fd; |
270 | ||
271 | error_socket: | |
272 | new_sock->ops->close(new_sock); | |
273 | lttcomm_destroy_sock(new_sock); | |
274 | error: | |
275 | return ret; | |
276 | } | |
277 | ||
f28f9e44 JG |
278 | bool agent_tracing_is_enabled(void) |
279 | { | |
280 | int enabled; | |
281 | ||
282 | enabled = uatomic_read(&agent_tracing_enabled); | |
283 | assert(enabled != -1); | |
284 | return enabled == 1; | |
285 | } | |
286 | ||
2288467f JG |
287 | /* |
288 | * Write agent TCP port using the rundir. | |
289 | */ | |
290 | static int write_agent_port(uint16_t port) | |
291 | { | |
292 | return utils_create_pid_file((pid_t) port, | |
293 | config.agent_port_file_path.value); | |
294 | } | |
295 | ||
4d076222 DG |
296 | /* |
297 | * This thread manage application notify communication. | |
298 | */ | |
7baf7871 | 299 | static void *thread_agent_management(void *data) |
4d076222 DG |
300 | { |
301 | int i, ret, pollfd; | |
302 | uint32_t revents, nb_fd; | |
303 | struct lttng_poll_event events; | |
304 | struct lttcomm_sock *reg_sock; | |
7baf7871 JG |
305 | struct lttng_pipe *quit_pipe = data; |
306 | const int quit_pipe_read_fd = lttng_pipe_get_readfd(quit_pipe); | |
4d076222 | 307 | |
022d91ba | 308 | DBG("[agent-thread] Manage agent application registration."); |
4d076222 DG |
309 | |
310 | rcu_register_thread(); | |
311 | rcu_thread_online(); | |
312 | ||
022d91ba DG |
313 | /* Agent initialization call MUST be called before starting the thread. */ |
314 | assert(agent_apps_ht_by_sock); | |
f20baf8e | 315 | |
7baf7871 JG |
316 | /* Create pollset with size 2, quit pipe and registration socket. */ |
317 | ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC); | |
4d076222 DG |
318 | if (ret < 0) { |
319 | goto error_poll_create; | |
320 | } | |
321 | ||
7baf7871 JG |
322 | ret = lttng_poll_add(&events, quit_pipe_read_fd, |
323 | LPOLLIN | LPOLLERR); | |
324 | if (ret < 0) { | |
325 | goto error_tcp_socket; | |
326 | } | |
327 | ||
4d076222 | 328 | reg_sock = init_tcp_socket(); |
2288467f JG |
329 | if (reg_sock) { |
330 | uint16_t port; | |
331 | ||
332 | assert(lttcomm_sock_get_port(reg_sock, &port) == 0); | |
333 | ||
334 | ret = write_agent_port(port); | |
335 | if (ret) { | |
336 | ERR("[agent-thread] Failed to create agent port file: agent tracing will be unavailable"); | |
337 | /* Don't prevent the launch of the sessiond on error. */ | |
338 | sessiond_notify_ready(); | |
339 | goto error; | |
340 | } | |
341 | } else { | |
342 | /* Don't prevent the launch of the sessiond on error. */ | |
343 | sessiond_notify_ready(); | |
344 | goto error_tcp_socket; | |
345 | } | |
f28f9e44 JG |
346 | |
347 | /* | |
348 | * Signal that the agent thread is ready. The command thread | |
349 | * may start to query whether or not agent tracing is enabled. | |
350 | */ | |
2288467f | 351 | uatomic_set(&agent_tracing_enabled, 1); |
7eac7803 | 352 | sessiond_notify_ready(); |
4d076222 | 353 | |
427392b4 | 354 | /* Add TCP socket to poll set. */ |
4d076222 DG |
355 | ret = lttng_poll_add(&events, reg_sock->fd, |
356 | LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP); | |
357 | if (ret < 0) { | |
358 | goto error; | |
359 | } | |
360 | ||
361 | while (1) { | |
546f19b5 | 362 | DBG3("[agent-thread] Manage agent polling"); |
4d076222 DG |
363 | |
364 | /* Inifinite blocking call, waiting for transmission */ | |
365 | restart: | |
366 | ret = lttng_poll_wait(&events, -1); | |
7fa2082e MD |
367 | DBG3("[agent-thread] Manage agent return from poll on %d fds", |
368 | LTTNG_POLL_GETNB(&events)); | |
4d076222 DG |
369 | if (ret < 0) { |
370 | /* | |
371 | * Restart interrupted system call. | |
372 | */ | |
373 | if (errno == EINTR) { | |
374 | goto restart; | |
375 | } | |
376 | goto error; | |
377 | } | |
378 | nb_fd = ret; | |
022d91ba | 379 | DBG3("[agent-thread] %d fd ready", nb_fd); |
4d076222 DG |
380 | |
381 | for (i = 0; i < nb_fd; i++) { | |
382 | /* Fetch once the poll data */ | |
383 | revents = LTTNG_POLL_GETEV(&events, i); | |
384 | pollfd = LTTNG_POLL_GETFD(&events, i); | |
385 | ||
fd20dac9 MD |
386 | if (!revents) { |
387 | /* No activity for this FD (poll implementation). */ | |
388 | continue; | |
389 | } | |
390 | ||
4d076222 | 391 | /* Thread quit pipe has been closed. Killing thread. */ |
7baf7871 | 392 | if (pollfd == quit_pipe_read_fd) { |
4d076222 DG |
393 | goto exit; |
394 | } | |
395 | ||
03e43155 | 396 | if (revents & LPOLLIN) { |
f20baf8e | 397 | int new_fd; |
022d91ba | 398 | struct agent_app *app = NULL; |
f20baf8e | 399 | |
f20baf8e | 400 | assert(pollfd == reg_sock->fd); |
1b500e7a | 401 | new_fd = handle_registration(reg_sock, &app); |
f20baf8e | 402 | if (new_fd < 0) { |
f20baf8e DG |
403 | continue; |
404 | } | |
1b500e7a DG |
405 | /* Should not have a NULL app on success. */ |
406 | assert(app); | |
f20baf8e | 407 | |
03e43155 MD |
408 | /* |
409 | * Since this is a command socket (write then read), | |
410 | * only add poll error event to only detect shutdown. | |
411 | */ | |
f20baf8e DG |
412 | ret = lttng_poll_add(&events, new_fd, |
413 | LPOLLERR | LPOLLHUP | LPOLLRDHUP); | |
414 | if (ret < 0) { | |
6a4e4039 | 415 | agent_destroy_app_by_sock(new_fd); |
f20baf8e DG |
416 | continue; |
417 | } | |
418 | ||
419 | /* Update newly registered app. */ | |
fefd409b | 420 | update_agent_app(app); |
1b500e7a DG |
421 | |
422 | /* On failure, the poll will detect it and clean it up. */ | |
03e43155 MD |
423 | ret = agent_send_registration_done(app); |
424 | if (ret < 0) { | |
425 | /* Removing from the poll set */ | |
426 | ret = lttng_poll_del(&events, new_fd); | |
427 | if (ret < 0) { | |
428 | goto error; | |
429 | } | |
430 | agent_destroy_app_by_sock(new_fd); | |
431 | continue; | |
432 | } | |
433 | } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) { | |
434 | /* Removing from the poll set */ | |
435 | ret = lttng_poll_del(&events, pollfd); | |
436 | if (ret < 0) { | |
437 | goto error; | |
438 | } | |
439 | agent_destroy_app_by_sock(pollfd); | |
4d076222 | 440 | } else { |
03e43155 MD |
441 | ERR("Unexpected poll events %u for sock %d", revents, pollfd); |
442 | goto error; | |
4d076222 DG |
443 | } |
444 | } | |
445 | } | |
446 | ||
447 | exit: | |
f20baf8e DG |
448 | /* Whatever happens, try to delete it and exit. */ |
449 | (void) lttng_poll_del(&events, reg_sock->fd); | |
4d076222 DG |
450 | error: |
451 | destroy_tcp_socket(reg_sock); | |
452 | error_tcp_socket: | |
453 | lttng_poll_clean(&events); | |
454 | error_poll_create: | |
2288467f | 455 | uatomic_set(&agent_tracing_enabled, 0); |
7baf7871 | 456 | DBG("[agent-thread] Cleaning up and stopping."); |
4d076222 DG |
457 | rcu_thread_offline(); |
458 | rcu_unregister_thread(); | |
459 | return NULL; | |
460 | } | |
7baf7871 JG |
461 | |
462 | static bool shutdown_agent_management_thread(void *data) | |
463 | { | |
464 | struct lttng_pipe *quit_pipe = data; | |
465 | const int write_fd = lttng_pipe_get_writefd(quit_pipe); | |
466 | ||
467 | return notify_thread_pipe(write_fd) == 1; | |
468 | } | |
469 | ||
45f6525f JG |
470 | static void cleanup_agent_management_thread(void *data) |
471 | { | |
472 | struct lttng_pipe *quit_pipe = data; | |
473 | ||
474 | lttng_pipe_destroy(quit_pipe); | |
475 | } | |
476 | ||
477 | bool launch_agent_management_thread(void) | |
7baf7871 JG |
478 | { |
479 | struct lttng_pipe *quit_pipe; | |
480 | struct lttng_thread *thread; | |
481 | ||
482 | quit_pipe = lttng_pipe_open(FD_CLOEXEC); | |
483 | if (!quit_pipe) { | |
484 | goto error; | |
485 | } | |
486 | thread = lttng_thread_create("Agent management", | |
487 | thread_agent_management, | |
488 | shutdown_agent_management_thread, | |
45f6525f | 489 | cleanup_agent_management_thread, |
7baf7871 JG |
490 | quit_pipe); |
491 | if (!thread) { | |
492 | goto error; | |
493 | } | |
494 | ||
495 | lttng_thread_put(thread); | |
496 | return true; | |
497 | error: | |
45f6525f | 498 | cleanup_agent_management_thread(quit_pipe); |
7baf7871 JG |
499 | return false; |
500 | } |