Commit | Line | Data |
---|---|---|
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" | |
4d076222 | 34 | |
f28f9e44 JG |
35 | static int agent_tracing_enabled = -1; |
36 | ||
4d076222 DG |
37 | /* |
38 | * Note that there is not port here. It's set after this URI is parsed so we | |
39 | * can let the user define a custom one. However, localhost is ALWAYS the | |
40 | * default listening address. | |
41 | */ | |
fa91dc52 MD |
42 | static const char *default_reg_uri = |
43 | "tcp://" DEFAULT_NETWORK_VIEWER_BIND_ADDRESS; | |
4d076222 | 44 | |
f20baf8e | 45 | /* |
022d91ba | 46 | * Update agent application using the given socket. This is done just after |
f20baf8e DG |
47 | * registration was successful. |
48 | * | |
49 | * This is a quite heavy call in terms of locking since the session list lock | |
50 | * AND session lock are acquired. | |
51 | */ | |
fefd409b | 52 | static void update_agent_app(struct agent_app *app) |
f20baf8e DG |
53 | { |
54 | struct ltt_session *session, *stmp; | |
55 | struct ltt_session_list *list; | |
56 | ||
57 | list = session_get_list(); | |
58 | assert(list); | |
59 | ||
60 | session_lock_list(); | |
61 | cds_list_for_each_entry_safe(session, stmp, &list->head, list) { | |
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); | |
74 | } | |
75 | session_unlock_list(); | |
76 | } | |
77 | ||
4d076222 DG |
78 | /* |
79 | * Create and init socket from uri. | |
80 | */ | |
81 | static struct lttcomm_sock *init_tcp_socket(void) | |
82 | { | |
83 | int ret; | |
84 | struct lttng_uri *uri = NULL; | |
85 | struct lttcomm_sock *sock = NULL; | |
2288467f JG |
86 | unsigned int port; |
87 | bool bind_succeeded = false; | |
4d076222 DG |
88 | |
89 | /* | |
90 | * This should never fail since the URI is hardcoded and the port is set | |
91 | * before this thread is launched. | |
92 | */ | |
93 | ret = uri_parse(default_reg_uri, &uri); | |
94 | assert(ret); | |
2288467f JG |
95 | assert(config.agent_tcp_port.begin > 0); |
96 | uri->port = config.agent_tcp_port.begin; | |
4d076222 DG |
97 | |
98 | sock = lttcomm_alloc_sock_from_uri(uri); | |
99 | uri_free(uri); | |
100 | if (sock == NULL) { | |
022d91ba | 101 | ERR("[agent-thread] agent allocating TCP socket"); |
4d076222 DG |
102 | goto error; |
103 | } | |
104 | ||
105 | ret = lttcomm_create_sock(sock); | |
106 | if (ret < 0) { | |
107 | goto error; | |
108 | } | |
109 | ||
2288467f JG |
110 | for (port = config.agent_tcp_port.begin; |
111 | port <= config.agent_tcp_port.end; port++) { | |
112 | ret = lttcomm_sock_set_port(sock, (uint16_t) port); | |
113 | if (ret) { | |
114 | ERR("[agent-thread] Failed to set port %u on socket", | |
115 | port); | |
116 | goto error; | |
117 | } | |
118 | DBG3("[agent-thread] Trying to bind on port %u", port); | |
119 | ret = sock->ops->bind(sock); | |
120 | if (!ret) { | |
121 | bind_succeeded = true; | |
122 | break; | |
123 | } | |
124 | ||
125 | if (errno == EADDRINUSE) { | |
126 | DBG("Failed to bind to port %u since it is already in use", | |
127 | port); | |
128 | } else { | |
129 | PERROR("Failed to bind to port %u", port); | |
130 | goto error; | |
131 | } | |
132 | } | |
133 | ||
134 | if (!bind_succeeded) { | |
135 | if (config.agent_tcp_port.begin == config.agent_tcp_port.end) { | |
136 | WARN("Another process is already using the agent port %i. " | |
137 | "Agent support will be deactivated.", | |
138 | config.agent_tcp_port.begin); | |
139 | goto error; | |
140 | } else { | |
141 | WARN("All ports in the range [%i, %i] are already in use. " | |
142 | "Agent support will be deactivated.", | |
143 | config.agent_tcp_port.begin, | |
144 | config.agent_tcp_port.end); | |
145 | goto error; | |
146 | } | |
4d076222 DG |
147 | } |
148 | ||
149 | ret = sock->ops->listen(sock, -1); | |
150 | if (ret < 0) { | |
151 | goto error; | |
152 | } | |
153 | ||
022d91ba | 154 | DBG("[agent-thread] Listening on TCP port %u and socket %d", |
2288467f | 155 | port, sock->fd); |
4d076222 DG |
156 | |
157 | return sock; | |
158 | ||
159 | error: | |
160 | if (sock) { | |
161 | lttcomm_destroy_sock(sock); | |
162 | } | |
163 | return NULL; | |
164 | } | |
165 | ||
166 | /* | |
167 | * Close and destroy the given TCP socket. | |
168 | */ | |
169 | static void destroy_tcp_socket(struct lttcomm_sock *sock) | |
170 | { | |
2288467f JG |
171 | int ret; |
172 | uint16_t port; | |
173 | ||
4d076222 DG |
174 | assert(sock); |
175 | ||
2288467f JG |
176 | ret = lttcomm_sock_get_port(sock, &port); |
177 | if (ret) { | |
178 | ERR("[agent-thread] Failed to get port of agent TCP socket"); | |
179 | port = 0; | |
180 | } | |
181 | ||
182 | DBG3("[agent-thread] Destroy TCP socket on port %" PRIu16, | |
183 | port); | |
4d076222 DG |
184 | |
185 | /* This will return gracefully if fd is invalid. */ | |
186 | sock->ops->close(sock); | |
187 | lttcomm_destroy_sock(sock); | |
188 | } | |
189 | ||
f20baf8e | 190 | /* |
022d91ba DG |
191 | * Handle a new agent registration using the reg socket. After that, a new |
192 | * agent application is added to the global hash table and attach to an UST app | |
1b500e7a | 193 | * object. If r_app is not NULL, the created app is set to the pointer. |
f20baf8e DG |
194 | * |
195 | * Return the new FD created upon accept() on success or else a negative errno | |
196 | * value. | |
197 | */ | |
1b500e7a | 198 | static int handle_registration(struct lttcomm_sock *reg_sock, |
022d91ba | 199 | struct agent_app **r_app) |
f20baf8e DG |
200 | { |
201 | int ret; | |
202 | pid_t pid; | |
9474416f | 203 | uint32_t major_version, minor_version; |
f20baf8e | 204 | ssize_t size; |
fefd409b | 205 | enum lttng_domain_type domain; |
022d91ba DG |
206 | struct agent_app *app; |
207 | struct agent_register_msg msg; | |
f20baf8e DG |
208 | struct lttcomm_sock *new_sock; |
209 | ||
210 | assert(reg_sock); | |
211 | ||
212 | new_sock = reg_sock->ops->accept(reg_sock); | |
213 | if (!new_sock) { | |
214 | ret = -ENOTCONN; | |
215 | goto error; | |
216 | } | |
217 | ||
218 | size = new_sock->ops->recvmsg(new_sock, &msg, sizeof(msg), 0); | |
219 | if (size < sizeof(msg)) { | |
79865500 | 220 | ret = -EINVAL; |
f20baf8e DG |
221 | goto error_socket; |
222 | } | |
fefd409b | 223 | domain = be32toh(msg.domain); |
f20baf8e | 224 | pid = be32toh(msg.pid); |
9474416f DG |
225 | major_version = be32toh(msg.major_version); |
226 | minor_version = be32toh(msg.minor_version); | |
227 | ||
228 | /* Test communication protocol version of the registring agent. */ | |
229 | if (major_version != AGENT_MAJOR_VERSION) { | |
230 | ret = -EINVAL; | |
231 | goto error_socket; | |
232 | } | |
233 | if (minor_version != AGENT_MINOR_VERSION) { | |
234 | ret = -EINVAL; | |
235 | goto error_socket; | |
236 | } | |
f20baf8e | 237 | |
fefd409b DG |
238 | DBG2("[agent-thread] New registration for pid %d domain %d on socket %d", |
239 | pid, domain, new_sock->fd); | |
f20baf8e | 240 | |
fefd409b | 241 | app = agent_create_app(pid, domain, new_sock); |
f20baf8e DG |
242 | if (!app) { |
243 | ret = -ENOMEM; | |
244 | goto error_socket; | |
245 | } | |
246 | ||
247 | /* | |
248 | * Add before assigning the socket value to the UST app so it can be found | |
249 | * concurrently. | |
250 | */ | |
022d91ba | 251 | agent_add_app(app); |
f20baf8e DG |
252 | |
253 | /* | |
022d91ba DG |
254 | * We don't need to attach the agent app to the app. If we ever do so, we |
255 | * should consider both registration order of agent before app and app | |
256 | * before agent. | |
f20baf8e | 257 | */ |
f20baf8e | 258 | |
1b500e7a DG |
259 | if (r_app) { |
260 | *r_app = app; | |
261 | } | |
262 | ||
f20baf8e DG |
263 | return new_sock->fd; |
264 | ||
265 | error_socket: | |
266 | new_sock->ops->close(new_sock); | |
267 | lttcomm_destroy_sock(new_sock); | |
268 | error: | |
269 | return ret; | |
270 | } | |
271 | ||
f28f9e44 JG |
272 | bool agent_tracing_is_enabled(void) |
273 | { | |
274 | int enabled; | |
275 | ||
276 | enabled = uatomic_read(&agent_tracing_enabled); | |
277 | assert(enabled != -1); | |
278 | return enabled == 1; | |
279 | } | |
280 | ||
2288467f JG |
281 | /* |
282 | * Write agent TCP port using the rundir. | |
283 | */ | |
284 | static int write_agent_port(uint16_t port) | |
285 | { | |
286 | return utils_create_pid_file((pid_t) port, | |
287 | config.agent_port_file_path.value); | |
288 | } | |
289 | ||
4d076222 DG |
290 | /* |
291 | * This thread manage application notify communication. | |
292 | */ | |
022d91ba | 293 | void *agent_thread_manage_registration(void *data) |
4d076222 DG |
294 | { |
295 | int i, ret, pollfd; | |
296 | uint32_t revents, nb_fd; | |
297 | struct lttng_poll_event events; | |
298 | struct lttcomm_sock *reg_sock; | |
299 | ||
022d91ba | 300 | DBG("[agent-thread] Manage agent application registration."); |
4d076222 DG |
301 | |
302 | rcu_register_thread(); | |
303 | rcu_thread_online(); | |
304 | ||
022d91ba DG |
305 | /* Agent initialization call MUST be called before starting the thread. */ |
306 | assert(agent_apps_ht_by_sock); | |
f20baf8e | 307 | |
4d076222 DG |
308 | /* Create pollset with size 2, quit pipe and socket. */ |
309 | ret = sessiond_set_thread_pollset(&events, 2); | |
310 | if (ret < 0) { | |
04fd2d2e | 311 | sessiond_notify_ready(); |
4d076222 DG |
312 | goto error_poll_create; |
313 | } | |
314 | ||
315 | reg_sock = init_tcp_socket(); | |
2288467f JG |
316 | if (reg_sock) { |
317 | uint16_t port; | |
318 | ||
319 | assert(lttcomm_sock_get_port(reg_sock, &port) == 0); | |
320 | ||
321 | ret = write_agent_port(port); | |
322 | if (ret) { | |
323 | ERR("[agent-thread] Failed to create agent port file: agent tracing will be unavailable"); | |
324 | /* Don't prevent the launch of the sessiond on error. */ | |
325 | sessiond_notify_ready(); | |
326 | goto error; | |
327 | } | |
328 | } else { | |
329 | /* Don't prevent the launch of the sessiond on error. */ | |
330 | sessiond_notify_ready(); | |
331 | goto error_tcp_socket; | |
332 | } | |
f28f9e44 JG |
333 | |
334 | /* | |
335 | * Signal that the agent thread is ready. The command thread | |
336 | * may start to query whether or not agent tracing is enabled. | |
337 | */ | |
2288467f | 338 | uatomic_set(&agent_tracing_enabled, 1); |
7eac7803 | 339 | sessiond_notify_ready(); |
4d076222 | 340 | |
427392b4 | 341 | /* Add TCP socket to poll set. */ |
4d076222 DG |
342 | ret = lttng_poll_add(&events, reg_sock->fd, |
343 | LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP); | |
344 | if (ret < 0) { | |
345 | goto error; | |
346 | } | |
347 | ||
348 | while (1) { | |
546f19b5 | 349 | DBG3("[agent-thread] Manage agent polling"); |
4d076222 DG |
350 | |
351 | /* Inifinite blocking call, waiting for transmission */ | |
352 | restart: | |
353 | ret = lttng_poll_wait(&events, -1); | |
7fa2082e MD |
354 | DBG3("[agent-thread] Manage agent return from poll on %d fds", |
355 | LTTNG_POLL_GETNB(&events)); | |
4d076222 DG |
356 | if (ret < 0) { |
357 | /* | |
358 | * Restart interrupted system call. | |
359 | */ | |
360 | if (errno == EINTR) { | |
361 | goto restart; | |
362 | } | |
363 | goto error; | |
364 | } | |
365 | nb_fd = ret; | |
022d91ba | 366 | DBG3("[agent-thread] %d fd ready", nb_fd); |
4d076222 DG |
367 | |
368 | for (i = 0; i < nb_fd; i++) { | |
369 | /* Fetch once the poll data */ | |
370 | revents = LTTNG_POLL_GETEV(&events, i); | |
371 | pollfd = LTTNG_POLL_GETFD(&events, i); | |
372 | ||
fd20dac9 MD |
373 | if (!revents) { |
374 | /* No activity for this FD (poll implementation). */ | |
375 | continue; | |
376 | } | |
377 | ||
4d076222 DG |
378 | /* Thread quit pipe has been closed. Killing thread. */ |
379 | ret = sessiond_check_thread_quit_pipe(pollfd, revents); | |
380 | if (ret) { | |
381 | goto exit; | |
382 | } | |
383 | ||
03e43155 | 384 | if (revents & LPOLLIN) { |
f20baf8e | 385 | int new_fd; |
022d91ba | 386 | struct agent_app *app = NULL; |
f20baf8e | 387 | |
f20baf8e | 388 | assert(pollfd == reg_sock->fd); |
1b500e7a | 389 | new_fd = handle_registration(reg_sock, &app); |
f20baf8e | 390 | if (new_fd < 0) { |
f20baf8e DG |
391 | continue; |
392 | } | |
1b500e7a DG |
393 | /* Should not have a NULL app on success. */ |
394 | assert(app); | |
f20baf8e | 395 | |
03e43155 MD |
396 | /* |
397 | * Since this is a command socket (write then read), | |
398 | * only add poll error event to only detect shutdown. | |
399 | */ | |
f20baf8e DG |
400 | ret = lttng_poll_add(&events, new_fd, |
401 | LPOLLERR | LPOLLHUP | LPOLLRDHUP); | |
402 | if (ret < 0) { | |
6a4e4039 | 403 | agent_destroy_app_by_sock(new_fd); |
f20baf8e DG |
404 | continue; |
405 | } | |
406 | ||
407 | /* Update newly registered app. */ | |
fefd409b | 408 | update_agent_app(app); |
1b500e7a DG |
409 | |
410 | /* On failure, the poll will detect it and clean it up. */ | |
03e43155 MD |
411 | ret = agent_send_registration_done(app); |
412 | if (ret < 0) { | |
413 | /* Removing from the poll set */ | |
414 | ret = lttng_poll_del(&events, new_fd); | |
415 | if (ret < 0) { | |
416 | goto error; | |
417 | } | |
418 | agent_destroy_app_by_sock(new_fd); | |
419 | continue; | |
420 | } | |
421 | } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) { | |
422 | /* Removing from the poll set */ | |
423 | ret = lttng_poll_del(&events, pollfd); | |
424 | if (ret < 0) { | |
425 | goto error; | |
426 | } | |
427 | agent_destroy_app_by_sock(pollfd); | |
4d076222 | 428 | } else { |
03e43155 MD |
429 | ERR("Unexpected poll events %u for sock %d", revents, pollfd); |
430 | goto error; | |
4d076222 DG |
431 | } |
432 | } | |
433 | } | |
434 | ||
435 | exit: | |
f20baf8e DG |
436 | /* Whatever happens, try to delete it and exit. */ |
437 | (void) lttng_poll_del(&events, reg_sock->fd); | |
4d076222 DG |
438 | error: |
439 | destroy_tcp_socket(reg_sock); | |
440 | error_tcp_socket: | |
441 | lttng_poll_clean(&events); | |
442 | error_poll_create: | |
2288467f | 443 | uatomic_set(&agent_tracing_enabled, 0); |
022d91ba | 444 | DBG("[agent-thread] is cleaning up and stopping."); |
4d076222 DG |
445 | |
446 | rcu_thread_offline(); | |
447 | rcu_unregister_thread(); | |
448 | return NULL; | |
449 | } |