Commit | Line | Data |
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1785d7f2 JG |
1 | /* |
2 | * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca> | |
3 | * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
4 | * 2013 - Jérémie Galarneau <jeremie.galarneau@efficios.com> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License, version 2 only, | |
8 | * as published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License along | |
16 | * with this program; if not, write to the Free Software Foundation, Inc., | |
17 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
18 | */ | |
19 | ||
20 | #include <stddef.h> | |
21 | #include <stdlib.h> | |
22 | #include <urcu.h> | |
23 | #include <common/futex.h> | |
24 | #include <common/macros.h> | |
25 | #include <common/utils.h> | |
26 | #include <sys/stat.h> | |
27 | ||
28 | #include "register.h" | |
29 | #include "lttng-sessiond.h" | |
30 | #include "testpoint.h" | |
31 | #include "health-sessiond.h" | |
32 | #include "fd-limit.h" | |
33 | #include "shm.h" | |
34 | #include "utils.h" | |
35 | #include "thread.h" | |
36 | ||
a13091b7 | 37 | struct thread_state { |
1785d7f2 JG |
38 | struct lttng_pipe *quit_pipe; |
39 | struct ust_cmd_queue *ust_cmd_queue; | |
9c9d917c | 40 | sem_t ready; |
86d0f119 | 41 | bool running; |
a13091b7 | 42 | int application_socket; |
1785d7f2 JG |
43 | }; |
44 | ||
45 | /* | |
46 | * Creates the application socket. | |
47 | */ | |
48 | static int create_application_socket(void) | |
49 | { | |
50 | int ret = 0; | |
51 | int apps_sock; | |
52 | const mode_t old_umask = umask(0); | |
53 | ||
54 | /* Create the application unix socket */ | |
55 | apps_sock = lttcomm_create_unix_sock(config.apps_unix_sock_path.value); | |
56 | if (apps_sock < 0) { | |
57 | ERR("Create unix sock failed: %s", config.apps_unix_sock_path.value); | |
58 | ret = -1; | |
59 | goto end; | |
60 | } | |
61 | ||
62 | /* Set the cloexec flag */ | |
63 | ret = utils_set_fd_cloexec(apps_sock); | |
64 | if (ret < 0) { | |
65 | ERR("Unable to set CLOEXEC flag to the app Unix socket (fd: %d). " | |
66 | "Continuing but note that the consumer daemon will have a " | |
67 | "reference to this socket on exec()", apps_sock); | |
68 | } | |
69 | ||
70 | /* File permission MUST be 666 */ | |
71 | ret = chmod(config.apps_unix_sock_path.value, | |
72 | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH); | |
73 | if (ret < 0) { | |
74 | PERROR("Set file permissions failed on %s", | |
75 | config.apps_unix_sock_path.value); | |
d9c6b5f2 | 76 | goto error_close_socket; |
1785d7f2 JG |
77 | } |
78 | ||
79 | DBG3("Session daemon application socket created (fd = %d) ", apps_sock); | |
80 | ret = apps_sock; | |
81 | end: | |
82 | umask(old_umask); | |
83 | return ret; | |
d9c6b5f2 JG |
84 | error_close_socket: |
85 | if (close(apps_sock)) { | |
86 | PERROR("Failed to close application socket in error path"); | |
87 | } | |
88 | apps_sock = -1; | |
89 | ret = -1; | |
90 | goto end; | |
1785d7f2 JG |
91 | } |
92 | ||
93 | /* | |
94 | * Notify UST applications using the shm mmap futex. | |
95 | */ | |
96 | static int notify_ust_apps(int active, bool is_root) | |
97 | { | |
98 | char *wait_shm_mmap; | |
99 | ||
100 | DBG("Notifying applications of session daemon state: %d", active); | |
101 | ||
102 | /* See shm.c for this call implying mmap, shm and futex calls */ | |
103 | wait_shm_mmap = shm_ust_get_mmap(config.wait_shm_path.value, is_root); | |
104 | if (wait_shm_mmap == NULL) { | |
105 | goto error; | |
106 | } | |
107 | ||
108 | /* Wake waiting process */ | |
109 | futex_wait_update((int32_t *) wait_shm_mmap, active); | |
110 | ||
111 | /* Apps notified successfully */ | |
112 | return 0; | |
113 | ||
114 | error: | |
115 | return -1; | |
116 | } | |
117 | ||
118 | static void cleanup_application_registration_thread(void *data) | |
119 | { | |
a13091b7 | 120 | struct thread_state *thread_state = data; |
1785d7f2 | 121 | |
a13091b7 JG |
122 | if (!data) { |
123 | return; | |
124 | } | |
125 | ||
126 | lttng_pipe_destroy(thread_state->quit_pipe); | |
127 | free(thread_state); | |
1785d7f2 JG |
128 | } |
129 | ||
a13091b7 | 130 | static void set_thread_status(struct thread_state *thread_state, bool running) |
9c9d917c | 131 | { |
86d0f119 | 132 | DBG("Marking application registration thread's state as %s", running ? "running" : "error"); |
a13091b7 JG |
133 | thread_state->running = running; |
134 | sem_post(&thread_state->ready); | |
9c9d917c JG |
135 | } |
136 | ||
a13091b7 | 137 | static bool wait_thread_status(struct thread_state *thread_state) |
9c9d917c JG |
138 | { |
139 | DBG("Waiting for application registration thread to be ready"); | |
a13091b7 JG |
140 | sem_wait(&thread_state->ready); |
141 | if (thread_state->running) { | |
86d0f119 JG |
142 | DBG("Application registration thread is ready"); |
143 | } else { | |
144 | ERR("Initialization of application registration thread failed"); | |
145 | } | |
146 | ||
a13091b7 | 147 | return thread_state->running; |
86d0f119 JG |
148 | } |
149 | ||
150 | static void thread_init_cleanup(void *data) | |
151 | { | |
a13091b7 | 152 | struct thread_state *thread_state = data; |
86d0f119 | 153 | |
a13091b7 | 154 | set_thread_status(thread_state, false); |
9c9d917c JG |
155 | } |
156 | ||
1785d7f2 JG |
157 | /* |
158 | * This thread manage application registration. | |
159 | */ | |
160 | static void *thread_application_registration(void *data) | |
161 | { | |
162 | int sock = -1, i, ret, pollfd, err = -1; | |
1785d7f2 JG |
163 | uint32_t revents, nb_fd; |
164 | struct lttng_poll_event events; | |
165 | /* | |
166 | * Gets allocated in this thread, enqueued to a global queue, dequeued | |
167 | * and freed in the manage apps thread. | |
168 | */ | |
169 | struct ust_command *ust_cmd = NULL; | |
170 | const bool is_root = (getuid() == 0); | |
a13091b7 JG |
171 | struct thread_state *thread_state = data; |
172 | const int application_socket = thread_state->application_socket; | |
1785d7f2 | 173 | const int quit_pipe_read_fd = lttng_pipe_get_readfd( |
a13091b7 | 174 | thread_state->quit_pipe); |
1785d7f2 JG |
175 | |
176 | DBG("[thread] Manage application registration started"); | |
177 | ||
86d0f119 | 178 | pthread_cleanup_push(thread_init_cleanup, NULL); |
1785d7f2 JG |
179 | health_register(health_sessiond, HEALTH_SESSIOND_TYPE_APP_REG); |
180 | ||
a13091b7 | 181 | ret = lttcomm_listen_unix_sock(application_socket); |
1785d7f2 JG |
182 | if (ret < 0) { |
183 | goto error_listen; | |
184 | } | |
185 | ||
86d0f119 JG |
186 | if (testpoint(sessiond_thread_registration_apps)) { |
187 | goto error_create_poll; | |
188 | } | |
9c9d917c | 189 | |
1785d7f2 JG |
190 | /* |
191 | * Pass 2 as size here for the thread quit pipe and apps_sock. Nothing | |
192 | * more will be added to this poll set. | |
193 | */ | |
194 | ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC); | |
195 | if (ret < 0) { | |
196 | goto error_create_poll; | |
197 | } | |
198 | ||
199 | /* Add the application registration socket */ | |
a13091b7 | 200 | ret = lttng_poll_add(&events, application_socket, LPOLLIN | LPOLLRDHUP); |
1785d7f2 JG |
201 | if (ret < 0) { |
202 | goto error_poll_add; | |
203 | } | |
204 | ||
205 | /* Add the application registration socket */ | |
206 | ret = lttng_poll_add(&events, quit_pipe_read_fd, LPOLLIN | LPOLLRDHUP); | |
207 | if (ret < 0) { | |
208 | goto error_poll_add; | |
209 | } | |
210 | ||
a13091b7 JG |
211 | set_thread_status(thread_state, true); |
212 | pthread_cleanup_pop(0); | |
1785d7f2 JG |
213 | |
214 | while (1) { | |
215 | DBG("Accepting application registration"); | |
216 | ||
217 | /* Inifinite blocking call, waiting for transmission */ | |
218 | restart: | |
219 | health_poll_entry(); | |
220 | ret = lttng_poll_wait(&events, -1); | |
221 | health_poll_exit(); | |
222 | if (ret < 0) { | |
223 | /* | |
224 | * Restart interrupted system call. | |
225 | */ | |
226 | if (errno == EINTR) { | |
227 | goto restart; | |
228 | } | |
229 | goto error; | |
230 | } | |
231 | ||
232 | nb_fd = ret; | |
233 | ||
234 | for (i = 0; i < nb_fd; i++) { | |
235 | health_code_update(); | |
236 | ||
237 | /* Fetch once the poll data */ | |
238 | revents = LTTNG_POLL_GETEV(&events, i); | |
239 | pollfd = LTTNG_POLL_GETFD(&events, i); | |
240 | ||
1785d7f2 JG |
241 | /* Thread quit pipe has been closed. Killing thread. */ |
242 | if (pollfd == quit_pipe_read_fd) { | |
243 | err = 0; | |
244 | goto exit; | |
245 | } else { | |
246 | /* Event on the registration socket */ | |
247 | if (revents & LPOLLIN) { | |
a13091b7 | 248 | sock = lttcomm_accept_unix_sock(application_socket); |
1785d7f2 JG |
249 | if (sock < 0) { |
250 | goto error; | |
251 | } | |
252 | ||
253 | /* | |
254 | * Set socket timeout for both receiving and ending. | |
255 | * app_socket_timeout is in seconds, whereas | |
256 | * lttcomm_setsockopt_rcv_timeout and | |
257 | * lttcomm_setsockopt_snd_timeout expect msec as | |
258 | * parameter. | |
259 | */ | |
260 | if (config.app_socket_timeout >= 0) { | |
261 | (void) lttcomm_setsockopt_rcv_timeout(sock, | |
262 | config.app_socket_timeout * 1000); | |
263 | (void) lttcomm_setsockopt_snd_timeout(sock, | |
264 | config.app_socket_timeout * 1000); | |
265 | } | |
266 | ||
267 | /* | |
268 | * Set the CLOEXEC flag. Return code is useless because | |
269 | * either way, the show must go on. | |
270 | */ | |
271 | (void) utils_set_fd_cloexec(sock); | |
272 | ||
273 | /* Create UST registration command for enqueuing */ | |
274 | ust_cmd = zmalloc(sizeof(struct ust_command)); | |
275 | if (ust_cmd == NULL) { | |
276 | PERROR("ust command zmalloc"); | |
277 | ret = close(sock); | |
278 | if (ret) { | |
279 | PERROR("close"); | |
280 | } | |
281 | goto error; | |
282 | } | |
283 | ||
284 | /* | |
285 | * Using message-based transmissions to ensure we don't | |
286 | * have to deal with partially received messages. | |
287 | */ | |
288 | ret = lttng_fd_get(LTTNG_FD_APPS, 1); | |
289 | if (ret < 0) { | |
290 | ERR("Exhausted file descriptors allowed for applications."); | |
291 | free(ust_cmd); | |
292 | ret = close(sock); | |
293 | if (ret) { | |
294 | PERROR("close"); | |
295 | } | |
296 | sock = -1; | |
297 | continue; | |
298 | } | |
299 | ||
300 | health_code_update(); | |
301 | ret = ust_app_recv_registration(sock, &ust_cmd->reg_msg); | |
302 | if (ret < 0) { | |
303 | free(ust_cmd); | |
304 | /* Close socket of the application. */ | |
305 | ret = close(sock); | |
306 | if (ret) { | |
307 | PERROR("close"); | |
308 | } | |
309 | lttng_fd_put(LTTNG_FD_APPS, 1); | |
310 | sock = -1; | |
311 | continue; | |
312 | } | |
313 | health_code_update(); | |
314 | ||
315 | ust_cmd->sock = sock; | |
316 | sock = -1; | |
317 | ||
318 | DBG("UST registration received with pid:%d ppid:%d uid:%d" | |
319 | " gid:%d sock:%d name:%s (version %d.%d)", | |
320 | ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid, | |
321 | ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid, | |
322 | ust_cmd->sock, ust_cmd->reg_msg.name, | |
323 | ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor); | |
324 | ||
325 | /* | |
326 | * Lock free enqueue the registration request. The red pill | |
327 | * has been taken! This apps will be part of the *system*. | |
328 | */ | |
a13091b7 JG |
329 | cds_wfcq_enqueue(&thread_state->ust_cmd_queue->head, |
330 | &thread_state->ust_cmd_queue->tail, | |
1785d7f2 JG |
331 | &ust_cmd->node); |
332 | ||
333 | /* | |
334 | * Wake the registration queue futex. Implicit memory | |
335 | * barrier with the exchange in cds_wfcq_enqueue. | |
336 | */ | |
a13091b7 | 337 | futex_nto1_wake(&thread_state->ust_cmd_queue->futex); |
1785d7f2 JG |
338 | } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) { |
339 | ERR("Register apps socket poll error"); | |
340 | goto error; | |
341 | } else { | |
342 | ERR("Unexpected poll events %u for sock %d", revents, pollfd); | |
343 | goto error; | |
344 | } | |
345 | } | |
346 | } | |
347 | } | |
348 | ||
349 | exit: | |
350 | error: | |
351 | /* Notify that the registration thread is gone */ | |
352 | notify_ust_apps(0, is_root); | |
353 | ||
a13091b7 JG |
354 | ret = close(application_socket); |
355 | if (ret) { | |
356 | PERROR("Failed to close application registration socket"); | |
1785d7f2 JG |
357 | } |
358 | if (sock >= 0) { | |
359 | ret = close(sock); | |
360 | if (ret) { | |
a13091b7 | 361 | PERROR("Failed to close application socket"); |
1785d7f2 JG |
362 | } |
363 | lttng_fd_put(LTTNG_FD_APPS, 1); | |
364 | } | |
365 | unlink(config.apps_unix_sock_path.value); | |
366 | ||
367 | error_poll_add: | |
368 | lttng_poll_clean(&events); | |
369 | error_listen: | |
370 | error_create_poll: | |
1785d7f2 JG |
371 | DBG("UST Registration thread cleanup complete"); |
372 | if (err) { | |
373 | health_error(); | |
374 | ERR("Health error occurred in %s", __func__); | |
375 | } | |
376 | health_unregister(health_sessiond); | |
377 | return NULL; | |
378 | } | |
379 | ||
380 | static bool shutdown_application_registration_thread(void *data) | |
381 | { | |
a13091b7 JG |
382 | struct thread_state *thread_state = data; |
383 | const int write_fd = lttng_pipe_get_writefd(thread_state->quit_pipe); | |
1785d7f2 JG |
384 | |
385 | return notify_thread_pipe(write_fd) == 1; | |
386 | } | |
387 | ||
bd9addf7 | 388 | struct lttng_thread *launch_application_registration_thread( |
1785d7f2 JG |
389 | struct ust_cmd_queue *cmd_queue) |
390 | { | |
a13091b7 | 391 | int ret; |
1785d7f2 | 392 | struct lttng_pipe *quit_pipe; |
a13091b7 JG |
393 | struct thread_state *thread_state = NULL; |
394 | struct lttng_thread *thread = NULL; | |
395 | const bool is_root = (getuid() == 0); | |
396 | int application_socket = -1; | |
1785d7f2 | 397 | |
a13091b7 JG |
398 | thread_state = zmalloc(sizeof(*thread_state)); |
399 | if (!thread_state) { | |
21fa020e JG |
400 | goto error_alloc; |
401 | } | |
402 | quit_pipe = lttng_pipe_open(FD_CLOEXEC); | |
403 | if (!quit_pipe) { | |
1785d7f2 JG |
404 | goto error; |
405 | } | |
a13091b7 JG |
406 | thread_state->quit_pipe = quit_pipe; |
407 | thread_state->ust_cmd_queue = cmd_queue; | |
408 | application_socket = create_application_socket(); | |
409 | if (application_socket < 0) { | |
410 | goto error; | |
411 | } | |
412 | thread_state->application_socket = application_socket; | |
413 | sem_init(&thread_state->ready, 0, 0); | |
1785d7f2 JG |
414 | |
415 | thread = lttng_thread_create("UST application registration", | |
416 | thread_application_registration, | |
417 | shutdown_application_registration_thread, | |
418 | cleanup_application_registration_thread, | |
a13091b7 | 419 | thread_state); |
1785d7f2 JG |
420 | if (!thread) { |
421 | goto error; | |
422 | } | |
a13091b7 JG |
423 | /* |
424 | * The application registration thread now owns the application socket | |
425 | * and the global thread state. The thread state is used to wait for | |
426 | * the thread's status, but its ownership now belongs to the thread. | |
427 | */ | |
428 | application_socket = -1; | |
429 | if (!wait_thread_status(thread_state)) { | |
430 | thread_state = NULL; | |
431 | goto error; | |
86d0f119 | 432 | } |
a13091b7 JG |
433 | |
434 | /* Notify all applications to register. */ | |
435 | ret = notify_ust_apps(1, is_root); | |
436 | if (ret < 0) { | |
437 | ERR("Failed to notify applications or create the wait shared memory.\n" | |
438 | "Execution continues but there might be problems for already\n" | |
439 | "running applications that wishes to register."); | |
440 | } | |
441 | ||
bd9addf7 | 442 | return thread; |
1785d7f2 | 443 | error: |
a13091b7 JG |
444 | lttng_thread_put(thread); |
445 | cleanup_application_registration_thread(thread_state); | |
446 | if (application_socket >= 0) { | |
447 | if (close(application_socket)) { | |
448 | PERROR("Failed to close application registration socket"); | |
449 | } | |
450 | } | |
21fa020e | 451 | error_alloc: |
bd9addf7 | 452 | return NULL; |
1785d7f2 | 453 | } |