Commit | Line | Data |
---|---|---|
2691221a MD |
1 | /* |
2 | * lttng-ust-comm.c | |
3 | * | |
4 | * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca> | |
5 | * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
6 | * | |
7 | * This library is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU Lesser General Public | |
9 | * License as published by the Free Software Foundation; only | |
10 | * version 2.1 of the License. | |
11 | * | |
12 | * This library is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * Lesser General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU Lesser General Public | |
18 | * License along with this library; if not, write to the Free Software | |
19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
20 | */ | |
21 | ||
22 | #include <sys/types.h> | |
23 | #include <sys/socket.h> | |
2629549e | 24 | #include <sys/prctl.h> |
2691221a MD |
25 | #include <unistd.h> |
26 | #include <errno.h> | |
d9e99d10 | 27 | #include <pthread.h> |
11ff9c7d MD |
28 | #include <semaphore.h> |
29 | #include <time.h> | |
1ea11eab | 30 | #include <assert.h> |
95259bd0 | 31 | #include <urcu/uatomic.h> |
1ea11eab | 32 | |
edaa1431 MD |
33 | #include <lttng-ust-comm.h> |
34 | #include <ust/usterr-signal-safe.h> | |
35 | #include <ust/lttng-ust-abi.h> | |
36 | #include <ust/tracepoint.h> | |
37 | ||
38 | /* | |
39 | * Has lttng ust comm constructor been called ? | |
40 | */ | |
41 | static int initialized; | |
42 | ||
1ea11eab MD |
43 | /* |
44 | * communication thread mutex. Held when handling a command, also held | |
45 | * by fork() to deal with removal of threads, and by exit path. | |
46 | */ | |
47 | static pthread_mutex_t lttng_ust_comm_mutex = PTHREAD_MUTEX_INITIALIZER; | |
48 | ||
49 | /* Should the ust comm thread quit ? */ | |
50 | static int lttng_ust_comm_should_quit; | |
51 | ||
11ff9c7d MD |
52 | /* |
53 | * Wait for either of these before continuing to the main | |
54 | * program: | |
55 | * - the register_done message from sessiond daemon | |
56 | * (will let the sessiond daemon enable sessions before main | |
57 | * starts.) | |
58 | * - sessiond daemon is not reachable. | |
59 | * - timeout (ensuring applications are resilient to session | |
60 | * daemon problems). | |
61 | */ | |
62 | static sem_t constructor_wait; | |
950aab0c MD |
63 | /* |
64 | * Doing this for both the global and local sessiond. | |
65 | */ | |
95259bd0 | 66 | static int sem_count = { 2 }; |
11ff9c7d | 67 | |
1ea11eab MD |
68 | /* |
69 | * Info about socket and associated listener thread. | |
70 | */ | |
71 | struct sock_info { | |
11ff9c7d | 72 | const char *name; |
1ea11eab MD |
73 | char sock_path[PATH_MAX]; |
74 | int socket; | |
75 | pthread_t ust_listener; /* listener thread */ | |
46050b1a | 76 | int root_handle; |
edaa1431 | 77 | int constructor_sem_posted;; |
1ea11eab | 78 | }; |
2691221a MD |
79 | |
80 | /* Socket from app (connect) to session daemon (listen) for communication */ | |
1ea11eab | 81 | struct sock_info global_apps = { |
11ff9c7d | 82 | .name = "global", |
1ea11eab MD |
83 | .sock_path = DEFAULT_GLOBAL_APPS_UNIX_SOCK, |
84 | .socket = -1, | |
46050b1a | 85 | .root_handle = -1, |
1ea11eab | 86 | }; |
2691221a MD |
87 | |
88 | /* TODO: allow global_apps_sock_path override */ | |
89 | ||
1ea11eab | 90 | struct sock_info local_apps = { |
11ff9c7d | 91 | .name = "local", |
1ea11eab | 92 | .socket = -1, |
46050b1a | 93 | .root_handle = -1, |
1ea11eab | 94 | }; |
2691221a | 95 | |
edaa1431 MD |
96 | extern void ltt_ring_buffer_client_overwrite_init(void); |
97 | extern void ltt_ring_buffer_client_discard_init(void); | |
98 | extern void ltt_ring_buffer_metadata_client_init(void); | |
99 | extern void ltt_ring_buffer_client_overwrite_exit(void); | |
100 | extern void ltt_ring_buffer_client_discard_exit(void); | |
101 | extern void ltt_ring_buffer_metadata_client_exit(void); | |
102 | ||
2691221a | 103 | static |
9eb62b9c | 104 | int setup_local_apps_socket(void) |
2691221a MD |
105 | { |
106 | const char *home_dir; | |
2691221a MD |
107 | |
108 | home_dir = (const char *) getenv("HOME"); | |
109 | if (!home_dir) | |
110 | return -ENOENT; | |
1ea11eab | 111 | snprintf(local_apps.sock_path, PATH_MAX, |
2691221a | 112 | DEFAULT_HOME_APPS_UNIX_SOCK, home_dir); |
2691221a MD |
113 | return 0; |
114 | } | |
115 | ||
116 | static | |
117 | int register_app_to_sessiond(int socket) | |
118 | { | |
119 | ssize_t ret; | |
2629549e | 120 | int prctl_ret; |
2691221a | 121 | struct { |
e44418f3 MD |
122 | uint32_t major; |
123 | uint32_t minor; | |
2691221a | 124 | pid_t pid; |
5c33bde8 | 125 | pid_t ppid; |
2691221a | 126 | uid_t uid; |
83610856 | 127 | gid_t gid; |
2629549e | 128 | char name[16]; /* process name */ |
2691221a MD |
129 | } reg_msg; |
130 | ||
e44418f3 MD |
131 | reg_msg.major = LTTNG_UST_COMM_VERSION_MAJOR; |
132 | reg_msg.minor = LTTNG_UST_COMM_VERSION_MINOR; | |
2691221a | 133 | reg_msg.pid = getpid(); |
5c33bde8 | 134 | reg_msg.ppid = getppid(); |
2691221a | 135 | reg_msg.uid = getuid(); |
83610856 | 136 | reg_msg.gid = getgid(); |
2629549e MD |
137 | prctl_ret = prctl(PR_GET_NAME, (unsigned long) reg_msg.name, 0, 0, 0); |
138 | if (prctl_ret) { | |
139 | ERR("Error executing prctl"); | |
140 | return -errno; | |
141 | } | |
2691221a MD |
142 | |
143 | ret = lttcomm_send_unix_sock(socket, ®_msg, sizeof(reg_msg)); | |
144 | if (ret >= 0 && ret != sizeof(reg_msg)) | |
145 | return -EIO; | |
146 | return ret; | |
147 | } | |
148 | ||
d9e99d10 | 149 | static |
d3a492d1 | 150 | int send_reply(int sock, struct lttcomm_ust_reply *lur) |
d9e99d10 | 151 | { |
9eb62b9c | 152 | ssize_t len; |
d3a492d1 | 153 | |
a4be8962 | 154 | len = lttcomm_send_unix_sock(sock, lur, sizeof(*lur)); |
d3a492d1 | 155 | switch (len) { |
a4be8962 | 156 | case sizeof(*lur): |
d3a492d1 MD |
157 | DBG("message successfully sent"); |
158 | return 0; | |
159 | case -1: | |
160 | if (errno == ECONNRESET) { | |
161 | printf("remote end closed connection\n"); | |
162 | return 0; | |
163 | } | |
164 | return -1; | |
165 | default: | |
166 | printf("incorrect message size: %zd\n", len); | |
167 | return -1; | |
168 | } | |
169 | } | |
170 | ||
171 | static | |
edaa1431 | 172 | int handle_register_done(struct sock_info *sock_info) |
11ff9c7d MD |
173 | { |
174 | int ret; | |
175 | ||
edaa1431 MD |
176 | if (sock_info->constructor_sem_posted) |
177 | return 0; | |
178 | sock_info->constructor_sem_posted = 1; | |
95259bd0 MD |
179 | ret = uatomic_add_return(&sem_count, -1); |
180 | if (ret == 0) { | |
181 | ret = sem_post(&constructor_wait); | |
182 | assert(!ret); | |
183 | } | |
11ff9c7d MD |
184 | return 0; |
185 | } | |
186 | ||
187 | static | |
188 | int handle_message(struct sock_info *sock_info, | |
189 | int sock, struct lttcomm_ust_msg *lum) | |
d3a492d1 | 190 | { |
1ea11eab | 191 | int ret = 0; |
46050b1a MD |
192 | const struct objd_ops *ops; |
193 | struct lttcomm_ust_reply lur; | |
1ea11eab MD |
194 | |
195 | pthread_mutex_lock(<tng_ust_comm_mutex); | |
196 | ||
46050b1a MD |
197 | memset(&lur, 0, sizeof(lur)); |
198 | ||
1ea11eab | 199 | if (lttng_ust_comm_should_quit) { |
46050b1a | 200 | ret = -EPERM; |
1ea11eab MD |
201 | goto end; |
202 | } | |
9eb62b9c | 203 | |
46050b1a MD |
204 | ops = objd_ops(lum->handle); |
205 | if (!ops) { | |
206 | ret = -ENOENT; | |
207 | goto end; | |
1ea11eab | 208 | } |
46050b1a MD |
209 | |
210 | switch (lum->cmd) { | |
11ff9c7d MD |
211 | case LTTNG_UST_REGISTER_DONE: |
212 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
edaa1431 | 213 | ret = handle_register_done(sock_info); |
11ff9c7d MD |
214 | else |
215 | ret = -EINVAL; | |
216 | break; | |
46050b1a MD |
217 | case LTTNG_UST_RELEASE: |
218 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
219 | ret = -EPERM; | |
220 | else | |
221 | ret = objd_unref(lum->handle); | |
d9e99d10 MD |
222 | break; |
223 | default: | |
46050b1a MD |
224 | if (ops->cmd) |
225 | ret = ops->cmd(lum->handle, lum->cmd, | |
226 | (unsigned long) &lum->u); | |
227 | else | |
228 | ret = -ENOSYS; | |
229 | break; | |
d9e99d10 | 230 | } |
46050b1a | 231 | |
1ea11eab | 232 | end: |
46050b1a MD |
233 | lur.handle = lum->handle; |
234 | lur.cmd = lum->cmd; | |
235 | lur.ret_val = ret; | |
236 | if (ret >= 0) { | |
237 | lur.ret_code = LTTCOMM_OK; | |
238 | } else { | |
239 | lur.ret_code = LTTCOMM_SESSION_FAIL; | |
240 | } | |
241 | ret = send_reply(sock, &lur); | |
242 | ||
1ea11eab MD |
243 | pthread_mutex_unlock(<tng_ust_comm_mutex); |
244 | return ret; | |
d9e99d10 MD |
245 | } |
246 | ||
46050b1a MD |
247 | static |
248 | void cleanup_sock_info(struct sock_info *sock_info) | |
249 | { | |
250 | int ret; | |
251 | ||
252 | if (sock_info->socket != -1) { | |
253 | ret = close(sock_info->socket); | |
254 | if (ret) { | |
255 | ERR("Error closing local apps socket"); | |
256 | } | |
257 | sock_info->socket = -1; | |
258 | } | |
259 | if (sock_info->root_handle != -1) { | |
260 | ret = objd_unref(sock_info->root_handle); | |
261 | if (ret) { | |
262 | ERR("Error unref root handle"); | |
263 | } | |
264 | sock_info->root_handle = -1; | |
265 | } | |
266 | } | |
267 | ||
1ea11eab MD |
268 | /* |
269 | * This thread does not allocate any resource, except within | |
270 | * handle_message, within mutex protection. This mutex protects against | |
271 | * fork and exit. | |
272 | * The other moment it allocates resources is at socket connexion, which | |
273 | * is also protected by the mutex. | |
274 | */ | |
d9e99d10 MD |
275 | static |
276 | void *ust_listener_thread(void *arg) | |
277 | { | |
1ea11eab MD |
278 | struct sock_info *sock_info = arg; |
279 | int sock, ret; | |
d9e99d10 | 280 | |
9eb62b9c MD |
281 | /* Restart trying to connect to the session daemon */ |
282 | restart: | |
1ea11eab MD |
283 | pthread_mutex_lock(<tng_ust_comm_mutex); |
284 | ||
285 | if (lttng_ust_comm_should_quit) { | |
286 | pthread_mutex_unlock(<tng_ust_comm_mutex); | |
287 | goto quit; | |
288 | } | |
9eb62b9c | 289 | |
1ea11eab MD |
290 | if (sock_info->socket != -1) { |
291 | ret = close(sock_info->socket); | |
292 | if (ret) { | |
11ff9c7d | 293 | ERR("Error closing %s apps socket", sock_info->name); |
1ea11eab MD |
294 | } |
295 | sock_info->socket = -1; | |
296 | } | |
46050b1a | 297 | |
9eb62b9c MD |
298 | /* Check for sessiond availability with pipe TODO */ |
299 | ||
300 | /* Register */ | |
1ea11eab | 301 | ret = lttcomm_connect_unix_sock(sock_info->sock_path); |
9eb62b9c | 302 | if (ret < 0) { |
11ff9c7d MD |
303 | ERR("Error connecting to %s apps socket", sock_info->name); |
304 | /* | |
305 | * If we cannot find the sessiond daemon, don't delay | |
306 | * constructor execution. | |
307 | */ | |
edaa1431 | 308 | ret = handle_register_done(sock_info); |
11ff9c7d | 309 | assert(!ret); |
1ea11eab | 310 | pthread_mutex_unlock(<tng_ust_comm_mutex); |
4eef2998 | 311 | sleep(5); |
1ea11eab | 312 | goto restart; |
46050b1a MD |
313 | } |
314 | ||
315 | sock_info->socket = sock = ret; | |
316 | ||
317 | /* | |
318 | * Create only one root handle per listener thread for the whole | |
319 | * process lifetime. | |
320 | */ | |
321 | if (sock_info->root_handle == -1) { | |
322 | ret = lttng_abi_create_root_handle(); | |
323 | if (ret) { | |
324 | ERR("Error creating root handle"); | |
325 | pthread_mutex_unlock(<tng_ust_comm_mutex); | |
326 | goto quit; | |
327 | } | |
328 | sock_info->root_handle = ret; | |
9eb62b9c | 329 | } |
1ea11eab | 330 | |
9eb62b9c MD |
331 | ret = register_app_to_sessiond(sock); |
332 | if (ret < 0) { | |
11ff9c7d MD |
333 | ERR("Error registering to %s apps socket", sock_info->name); |
334 | /* | |
335 | * If we cannot register to the sessiond daemon, don't | |
336 | * delay constructor execution. | |
337 | */ | |
edaa1431 | 338 | ret = handle_register_done(sock_info); |
11ff9c7d | 339 | assert(!ret); |
46050b1a | 340 | pthread_mutex_unlock(<tng_ust_comm_mutex); |
9eb62b9c MD |
341 | sleep(5); |
342 | goto restart; | |
343 | } | |
46050b1a MD |
344 | pthread_mutex_unlock(<tng_ust_comm_mutex); |
345 | ||
d9e99d10 MD |
346 | for (;;) { |
347 | ssize_t len; | |
e7723462 | 348 | struct lttcomm_ust_msg lum; |
d9e99d10 | 349 | |
e7723462 | 350 | len = lttcomm_recv_unix_sock(sock, &lum, sizeof(lum)); |
d9e99d10 MD |
351 | switch (len) { |
352 | case 0: /* orderly shutdown */ | |
11ff9c7d | 353 | DBG("%s ltt-sessiond has performed an orderly shutdown\n", sock_info->name); |
d9e99d10 | 354 | goto end; |
e7723462 | 355 | case sizeof(lum): |
d9e99d10 | 356 | DBG("message received\n"); |
11ff9c7d | 357 | ret = handle_message(sock_info, sock, &lum); |
2a80c9d8 | 358 | if (ret < 0) { |
11ff9c7d | 359 | ERR("Error handling message for %s socket", sock_info->name); |
d9e99d10 MD |
360 | } |
361 | continue; | |
362 | case -1: | |
363 | if (errno == ECONNRESET) { | |
11ff9c7d | 364 | ERR("%s remote end closed connection\n", sock_info->name); |
d9e99d10 MD |
365 | goto end; |
366 | } | |
367 | goto end; | |
368 | default: | |
11ff9c7d | 369 | ERR("incorrect message size (%s socket): %zd\n", sock_info->name, len); |
d9e99d10 MD |
370 | continue; |
371 | } | |
372 | ||
373 | } | |
374 | end: | |
9eb62b9c | 375 | goto restart; /* try to reconnect */ |
1ea11eab | 376 | quit: |
d9e99d10 MD |
377 | return NULL; |
378 | } | |
379 | ||
cf12a773 MD |
380 | /* |
381 | * Return values: -1: don't wait. 0: wait forever. 1: timeout wait. | |
382 | */ | |
11ff9c7d MD |
383 | static |
384 | int get_timeout(struct timespec *constructor_timeout) | |
385 | { | |
cf12a773 MD |
386 | long constructor_delay_ms = LTTNG_UST_DEFAULT_CONSTRUCTOR_TIMEOUT_MS; |
387 | char *str_delay; | |
11ff9c7d MD |
388 | int ret; |
389 | ||
cf12a773 MD |
390 | str_delay = getenv("UST_REGISTER_TIMEOUT"); |
391 | if (str_delay) { | |
392 | constructor_delay_ms = strtol(str_delay, NULL, 10); | |
393 | } | |
394 | ||
395 | switch (constructor_delay_ms) { | |
396 | case -1:/* fall-through */ | |
397 | case 0: | |
398 | return constructor_delay_ms; | |
399 | default: | |
400 | break; | |
401 | } | |
402 | ||
403 | /* | |
404 | * If we are unable to find the current time, don't wait. | |
405 | */ | |
406 | ret = clock_gettime(CLOCK_REALTIME, constructor_timeout); | |
407 | if (ret) { | |
408 | return -1; | |
409 | } | |
95259bd0 MD |
410 | constructor_timeout->tv_sec += constructor_delay_ms / 1000UL; |
411 | constructor_timeout->tv_nsec += | |
412 | (constructor_delay_ms % 1000UL) * 1000000UL; | |
11ff9c7d MD |
413 | if (constructor_timeout->tv_nsec >= 1000000000UL) { |
414 | constructor_timeout->tv_sec++; | |
415 | constructor_timeout->tv_nsec -= 1000000000UL; | |
416 | } | |
cf12a773 | 417 | return 1; |
11ff9c7d | 418 | } |
d9e99d10 | 419 | |
2691221a MD |
420 | /* |
421 | * sessiond monitoring thread: monitor presence of global and per-user | |
422 | * sessiond by polling the application common named pipe. | |
423 | */ | |
424 | /* TODO */ | |
425 | ||
edaa1431 | 426 | void __attribute__((constructor)) lttng_ust_init(void) |
2691221a | 427 | { |
11ff9c7d | 428 | struct timespec constructor_timeout; |
cf12a773 | 429 | int timeout_mode; |
2691221a MD |
430 | int ret; |
431 | ||
edaa1431 MD |
432 | if (uatomic_xchg(&initialized, 1) == 1) |
433 | return; | |
434 | ||
435 | /* | |
436 | * We want precise control over the order in which we construct | |
437 | * our sub-libraries vs starting to receive commands from | |
438 | * sessiond (otherwise leading to errors when trying to create | |
439 | * sessiond before the init functions are completed). | |
440 | */ | |
2691221a | 441 | init_usterr(); |
edaa1431 MD |
442 | init_tracepoint(); |
443 | ltt_ring_buffer_metadata_client_init(); | |
444 | ltt_ring_buffer_client_overwrite_init(); | |
445 | ltt_ring_buffer_client_discard_init(); | |
2691221a | 446 | |
cf12a773 | 447 | timeout_mode = get_timeout(&constructor_timeout); |
11ff9c7d | 448 | |
95259bd0 | 449 | ret = sem_init(&constructor_wait, 0, 0); |
11ff9c7d MD |
450 | assert(!ret); |
451 | ||
9eb62b9c | 452 | ret = setup_local_apps_socket(); |
2691221a | 453 | if (ret) { |
9eb62b9c | 454 | ERR("Error setting up to local apps socket"); |
2691221a | 455 | } |
11ff9c7d | 456 | |
1ea11eab MD |
457 | ret = pthread_create(&global_apps.ust_listener, NULL, |
458 | ust_listener_thread, &global_apps); | |
1ea11eab MD |
459 | ret = pthread_create(&local_apps.ust_listener, NULL, |
460 | ust_listener_thread, &local_apps); | |
11ff9c7d | 461 | |
cf12a773 MD |
462 | switch (timeout_mode) { |
463 | case 1: /* timeout wait */ | |
95259bd0 MD |
464 | do { |
465 | ret = sem_timedwait(&constructor_wait, | |
466 | &constructor_timeout); | |
467 | } while (ret < 0 && errno == EINTR); | |
cf12a773 MD |
468 | if (ret < 0 && errno == ETIMEDOUT) { |
469 | ERR("Timed out waiting for ltt-sessiond"); | |
470 | } else { | |
471 | assert(!ret); | |
472 | } | |
473 | break; | |
7b766b16 | 474 | case -1:/* wait forever */ |
95259bd0 MD |
475 | do { |
476 | ret = sem_wait(&constructor_wait); | |
477 | } while (ret < 0 && errno == EINTR); | |
11ff9c7d | 478 | assert(!ret); |
cf12a773 | 479 | break; |
7b766b16 | 480 | case 0: /* no timeout */ |
cf12a773 | 481 | break; |
11ff9c7d | 482 | } |
2691221a MD |
483 | } |
484 | ||
edaa1431 | 485 | void __attribute__((destructor)) lttng_ust_exit(void) |
2691221a MD |
486 | { |
487 | int ret; | |
488 | ||
9eb62b9c MD |
489 | /* |
490 | * Using pthread_cancel here because: | |
491 | * A) we don't want to hang application teardown. | |
492 | * B) the thread is not allocating any resource. | |
493 | */ | |
1ea11eab MD |
494 | |
495 | /* | |
496 | * Require the communication thread to quit. Synchronize with | |
497 | * mutexes to ensure it is not in a mutex critical section when | |
498 | * pthread_cancel is later called. | |
499 | */ | |
500 | pthread_mutex_lock(<tng_ust_comm_mutex); | |
501 | lttng_ust_comm_should_quit = 1; | |
502 | pthread_mutex_unlock(<tng_ust_comm_mutex); | |
503 | ||
504 | #if 0 | |
505 | ret = pthread_cancel(global_apps.ust_listener); | |
9eb62b9c MD |
506 | if (ret) { |
507 | ERR("Error cancelling global ust listener thread"); | |
2691221a | 508 | } |
1ea11eab | 509 | #endif //0 |
46050b1a MD |
510 | |
511 | cleanup_sock_info(&global_apps); | |
1ea11eab MD |
512 | |
513 | ret = pthread_cancel(local_apps.ust_listener); | |
9eb62b9c MD |
514 | if (ret) { |
515 | ERR("Error cancelling local ust listener thread"); | |
2691221a | 516 | } |
1ea11eab | 517 | |
46050b1a | 518 | cleanup_sock_info(&local_apps); |
1ea11eab | 519 | |
b35d179d | 520 | lttng_ust_abi_exit(); |
1ea11eab | 521 | ltt_events_exit(); |
edaa1431 MD |
522 | ltt_ring_buffer_client_discard_exit(); |
523 | ltt_ring_buffer_client_overwrite_exit(); | |
524 | ltt_ring_buffer_metadata_client_exit(); | |
525 | exit_tracepoint(); | |
2691221a | 526 | } |