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> | |
24 | #include <unistd.h> | |
25 | #include <errno.h> | |
b35d179d MD |
26 | #include <ust/lttng-ust-abi.h> |
27 | #include <lttng-ust-comm.h> | |
2691221a | 28 | #include <ust/usterr-signal-safe.h> |
d9e99d10 | 29 | #include <pthread.h> |
11ff9c7d MD |
30 | #include <semaphore.h> |
31 | #include <time.h> | |
1ea11eab MD |
32 | #include <assert.h> |
33 | ||
34 | /* | |
35 | * communication thread mutex. Held when handling a command, also held | |
36 | * by fork() to deal with removal of threads, and by exit path. | |
37 | */ | |
38 | static pthread_mutex_t lttng_ust_comm_mutex = PTHREAD_MUTEX_INITIALIZER; | |
39 | ||
40 | /* Should the ust comm thread quit ? */ | |
41 | static int lttng_ust_comm_should_quit; | |
42 | ||
11ff9c7d MD |
43 | /* |
44 | * Wait for either of these before continuing to the main | |
45 | * program: | |
46 | * - the register_done message from sessiond daemon | |
47 | * (will let the sessiond daemon enable sessions before main | |
48 | * starts.) | |
49 | * - sessiond daemon is not reachable. | |
50 | * - timeout (ensuring applications are resilient to session | |
51 | * daemon problems). | |
52 | */ | |
53 | static sem_t constructor_wait; | |
54 | ||
1ea11eab MD |
55 | /* |
56 | * Info about socket and associated listener thread. | |
57 | */ | |
58 | struct sock_info { | |
11ff9c7d | 59 | const char *name; |
1ea11eab MD |
60 | char sock_path[PATH_MAX]; |
61 | int socket; | |
62 | pthread_t ust_listener; /* listener thread */ | |
46050b1a | 63 | int root_handle; |
1ea11eab | 64 | }; |
2691221a MD |
65 | |
66 | /* Socket from app (connect) to session daemon (listen) for communication */ | |
1ea11eab | 67 | struct sock_info global_apps = { |
11ff9c7d | 68 | .name = "global", |
1ea11eab MD |
69 | .sock_path = DEFAULT_GLOBAL_APPS_UNIX_SOCK, |
70 | .socket = -1, | |
46050b1a | 71 | .root_handle = -1, |
1ea11eab | 72 | }; |
2691221a MD |
73 | |
74 | /* TODO: allow global_apps_sock_path override */ | |
75 | ||
1ea11eab | 76 | struct sock_info local_apps = { |
11ff9c7d | 77 | .name = "local", |
1ea11eab | 78 | .socket = -1, |
46050b1a | 79 | .root_handle = -1, |
1ea11eab | 80 | }; |
2691221a MD |
81 | |
82 | static | |
9eb62b9c | 83 | int setup_local_apps_socket(void) |
2691221a MD |
84 | { |
85 | const char *home_dir; | |
2691221a MD |
86 | |
87 | home_dir = (const char *) getenv("HOME"); | |
88 | if (!home_dir) | |
89 | return -ENOENT; | |
1ea11eab | 90 | snprintf(local_apps.sock_path, PATH_MAX, |
2691221a | 91 | DEFAULT_HOME_APPS_UNIX_SOCK, home_dir); |
2691221a MD |
92 | return 0; |
93 | } | |
94 | ||
95 | static | |
96 | int register_app_to_sessiond(int socket) | |
97 | { | |
98 | ssize_t ret; | |
99 | struct { | |
e44418f3 MD |
100 | uint32_t major; |
101 | uint32_t minor; | |
2691221a MD |
102 | pid_t pid; |
103 | uid_t uid; | |
104 | } reg_msg; | |
105 | ||
e44418f3 MD |
106 | reg_msg.major = LTTNG_UST_COMM_VERSION_MAJOR; |
107 | reg_msg.minor = LTTNG_UST_COMM_VERSION_MINOR; | |
2691221a MD |
108 | reg_msg.pid = getpid(); |
109 | reg_msg.uid = getuid(); | |
110 | ||
111 | ret = lttcomm_send_unix_sock(socket, ®_msg, sizeof(reg_msg)); | |
112 | if (ret >= 0 && ret != sizeof(reg_msg)) | |
113 | return -EIO; | |
114 | return ret; | |
115 | } | |
116 | ||
d9e99d10 | 117 | static |
d3a492d1 | 118 | int send_reply(int sock, struct lttcomm_ust_reply *lur) |
d9e99d10 | 119 | { |
9eb62b9c | 120 | ssize_t len; |
d3a492d1 | 121 | |
a4be8962 | 122 | len = lttcomm_send_unix_sock(sock, lur, sizeof(*lur)); |
d3a492d1 | 123 | switch (len) { |
a4be8962 | 124 | case sizeof(*lur): |
d3a492d1 MD |
125 | DBG("message successfully sent"); |
126 | return 0; | |
127 | case -1: | |
128 | if (errno == ECONNRESET) { | |
129 | printf("remote end closed connection\n"); | |
130 | return 0; | |
131 | } | |
132 | return -1; | |
133 | default: | |
134 | printf("incorrect message size: %zd\n", len); | |
135 | return -1; | |
136 | } | |
137 | } | |
138 | ||
139 | static | |
11ff9c7d MD |
140 | int handle_register_done(void) |
141 | { | |
142 | int ret; | |
143 | ||
144 | ret = sem_post(&constructor_wait); | |
145 | assert(!ret); | |
146 | return 0; | |
147 | } | |
148 | ||
149 | static | |
150 | int handle_message(struct sock_info *sock_info, | |
151 | int sock, struct lttcomm_ust_msg *lum) | |
d3a492d1 | 152 | { |
1ea11eab | 153 | int ret = 0; |
46050b1a MD |
154 | const struct objd_ops *ops; |
155 | struct lttcomm_ust_reply lur; | |
1ea11eab MD |
156 | |
157 | pthread_mutex_lock(<tng_ust_comm_mutex); | |
158 | ||
46050b1a MD |
159 | memset(&lur, 0, sizeof(lur)); |
160 | ||
1ea11eab | 161 | if (lttng_ust_comm_should_quit) { |
46050b1a | 162 | ret = -EPERM; |
1ea11eab MD |
163 | goto end; |
164 | } | |
9eb62b9c | 165 | |
46050b1a MD |
166 | ops = objd_ops(lum->handle); |
167 | if (!ops) { | |
168 | ret = -ENOENT; | |
169 | goto end; | |
1ea11eab | 170 | } |
46050b1a MD |
171 | |
172 | switch (lum->cmd) { | |
11ff9c7d MD |
173 | case LTTNG_UST_REGISTER_DONE: |
174 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
175 | ret = handle_register_done(); | |
176 | else | |
177 | ret = -EINVAL; | |
178 | break; | |
46050b1a MD |
179 | case LTTNG_UST_RELEASE: |
180 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
181 | ret = -EPERM; | |
182 | else | |
183 | ret = objd_unref(lum->handle); | |
d9e99d10 MD |
184 | break; |
185 | default: | |
46050b1a MD |
186 | if (ops->cmd) |
187 | ret = ops->cmd(lum->handle, lum->cmd, | |
188 | (unsigned long) &lum->u); | |
189 | else | |
190 | ret = -ENOSYS; | |
191 | break; | |
d9e99d10 | 192 | } |
46050b1a | 193 | |
1ea11eab | 194 | end: |
46050b1a MD |
195 | lur.handle = lum->handle; |
196 | lur.cmd = lum->cmd; | |
197 | lur.ret_val = ret; | |
198 | if (ret >= 0) { | |
199 | lur.ret_code = LTTCOMM_OK; | |
200 | } else { | |
201 | lur.ret_code = LTTCOMM_SESSION_FAIL; | |
202 | } | |
203 | ret = send_reply(sock, &lur); | |
204 | ||
1ea11eab MD |
205 | pthread_mutex_unlock(<tng_ust_comm_mutex); |
206 | return ret; | |
d9e99d10 MD |
207 | } |
208 | ||
46050b1a MD |
209 | static |
210 | void cleanup_sock_info(struct sock_info *sock_info) | |
211 | { | |
212 | int ret; | |
213 | ||
214 | if (sock_info->socket != -1) { | |
215 | ret = close(sock_info->socket); | |
216 | if (ret) { | |
217 | ERR("Error closing local apps socket"); | |
218 | } | |
219 | sock_info->socket = -1; | |
220 | } | |
221 | if (sock_info->root_handle != -1) { | |
222 | ret = objd_unref(sock_info->root_handle); | |
223 | if (ret) { | |
224 | ERR("Error unref root handle"); | |
225 | } | |
226 | sock_info->root_handle = -1; | |
227 | } | |
228 | } | |
229 | ||
1ea11eab MD |
230 | /* |
231 | * This thread does not allocate any resource, except within | |
232 | * handle_message, within mutex protection. This mutex protects against | |
233 | * fork and exit. | |
234 | * The other moment it allocates resources is at socket connexion, which | |
235 | * is also protected by the mutex. | |
236 | */ | |
d9e99d10 MD |
237 | static |
238 | void *ust_listener_thread(void *arg) | |
239 | { | |
1ea11eab MD |
240 | struct sock_info *sock_info = arg; |
241 | int sock, ret; | |
d9e99d10 | 242 | |
9eb62b9c MD |
243 | /* Restart trying to connect to the session daemon */ |
244 | restart: | |
1ea11eab MD |
245 | pthread_mutex_lock(<tng_ust_comm_mutex); |
246 | ||
247 | if (lttng_ust_comm_should_quit) { | |
248 | pthread_mutex_unlock(<tng_ust_comm_mutex); | |
249 | goto quit; | |
250 | } | |
9eb62b9c | 251 | |
1ea11eab MD |
252 | if (sock_info->socket != -1) { |
253 | ret = close(sock_info->socket); | |
254 | if (ret) { | |
11ff9c7d | 255 | ERR("Error closing %s apps socket", sock_info->name); |
1ea11eab MD |
256 | } |
257 | sock_info->socket = -1; | |
258 | } | |
46050b1a | 259 | |
9eb62b9c MD |
260 | /* Check for sessiond availability with pipe TODO */ |
261 | ||
262 | /* Register */ | |
1ea11eab | 263 | ret = lttcomm_connect_unix_sock(sock_info->sock_path); |
9eb62b9c | 264 | if (ret < 0) { |
11ff9c7d MD |
265 | ERR("Error connecting to %s apps socket", sock_info->name); |
266 | /* | |
267 | * If we cannot find the sessiond daemon, don't delay | |
268 | * constructor execution. | |
269 | */ | |
270 | ret = handle_register_done(); | |
271 | assert(!ret); | |
1ea11eab | 272 | pthread_mutex_unlock(<tng_ust_comm_mutex); |
4eef2998 | 273 | sleep(5); |
1ea11eab | 274 | goto restart; |
46050b1a MD |
275 | } |
276 | ||
277 | sock_info->socket = sock = ret; | |
278 | ||
279 | /* | |
280 | * Create only one root handle per listener thread for the whole | |
281 | * process lifetime. | |
282 | */ | |
283 | if (sock_info->root_handle == -1) { | |
284 | ret = lttng_abi_create_root_handle(); | |
285 | if (ret) { | |
286 | ERR("Error creating root handle"); | |
287 | pthread_mutex_unlock(<tng_ust_comm_mutex); | |
288 | goto quit; | |
289 | } | |
290 | sock_info->root_handle = ret; | |
9eb62b9c | 291 | } |
1ea11eab | 292 | |
9eb62b9c MD |
293 | ret = register_app_to_sessiond(sock); |
294 | if (ret < 0) { | |
11ff9c7d MD |
295 | ERR("Error registering to %s apps socket", sock_info->name); |
296 | /* | |
297 | * If we cannot register to the sessiond daemon, don't | |
298 | * delay constructor execution. | |
299 | */ | |
300 | ret = handle_register_done(); | |
301 | assert(!ret); | |
46050b1a | 302 | pthread_mutex_unlock(<tng_ust_comm_mutex); |
9eb62b9c MD |
303 | sleep(5); |
304 | goto restart; | |
305 | } | |
46050b1a MD |
306 | pthread_mutex_unlock(<tng_ust_comm_mutex); |
307 | ||
d9e99d10 MD |
308 | for (;;) { |
309 | ssize_t len; | |
e7723462 | 310 | struct lttcomm_ust_msg lum; |
d9e99d10 | 311 | |
e7723462 | 312 | len = lttcomm_recv_unix_sock(sock, &lum, sizeof(lum)); |
d9e99d10 MD |
313 | switch (len) { |
314 | case 0: /* orderly shutdown */ | |
11ff9c7d | 315 | DBG("%s ltt-sessiond has performed an orderly shutdown\n", sock_info->name); |
d9e99d10 | 316 | goto end; |
e7723462 | 317 | case sizeof(lum): |
d9e99d10 | 318 | DBG("message received\n"); |
11ff9c7d | 319 | ret = handle_message(sock_info, sock, &lum); |
2a80c9d8 | 320 | if (ret < 0) { |
11ff9c7d | 321 | ERR("Error handling message for %s socket", sock_info->name); |
d9e99d10 MD |
322 | } |
323 | continue; | |
324 | case -1: | |
325 | if (errno == ECONNRESET) { | |
11ff9c7d | 326 | ERR("%s remote end closed connection\n", sock_info->name); |
d9e99d10 MD |
327 | goto end; |
328 | } | |
329 | goto end; | |
330 | default: | |
11ff9c7d | 331 | ERR("incorrect message size (%s socket): %zd\n", sock_info->name, len); |
d9e99d10 MD |
332 | continue; |
333 | } | |
334 | ||
335 | } | |
336 | end: | |
9eb62b9c | 337 | goto restart; /* try to reconnect */ |
1ea11eab | 338 | quit: |
d9e99d10 MD |
339 | return NULL; |
340 | } | |
341 | ||
cf12a773 MD |
342 | /* |
343 | * Return values: -1: don't wait. 0: wait forever. 1: timeout wait. | |
344 | */ | |
11ff9c7d MD |
345 | static |
346 | int get_timeout(struct timespec *constructor_timeout) | |
347 | { | |
cf12a773 MD |
348 | long constructor_delay_ms = LTTNG_UST_DEFAULT_CONSTRUCTOR_TIMEOUT_MS; |
349 | char *str_delay; | |
11ff9c7d MD |
350 | int ret; |
351 | ||
cf12a773 MD |
352 | str_delay = getenv("UST_REGISTER_TIMEOUT"); |
353 | if (str_delay) { | |
354 | constructor_delay_ms = strtol(str_delay, NULL, 10); | |
355 | } | |
356 | ||
357 | switch (constructor_delay_ms) { | |
358 | case -1:/* fall-through */ | |
359 | case 0: | |
360 | return constructor_delay_ms; | |
361 | default: | |
362 | break; | |
363 | } | |
364 | ||
365 | /* | |
366 | * If we are unable to find the current time, don't wait. | |
367 | */ | |
368 | ret = clock_gettime(CLOCK_REALTIME, constructor_timeout); | |
369 | if (ret) { | |
370 | return -1; | |
371 | } | |
11ff9c7d | 372 | |
11ff9c7d | 373 | constructor_timeout->tv_nsec = |
cf12a773 | 374 | constructor_timeout->tv_nsec + (constructor_delay_ms * 1000000UL); |
11ff9c7d MD |
375 | if (constructor_timeout->tv_nsec >= 1000000000UL) { |
376 | constructor_timeout->tv_sec++; | |
377 | constructor_timeout->tv_nsec -= 1000000000UL; | |
378 | } | |
cf12a773 | 379 | return 1; |
11ff9c7d | 380 | } |
d9e99d10 | 381 | |
2691221a MD |
382 | /* |
383 | * sessiond monitoring thread: monitor presence of global and per-user | |
384 | * sessiond by polling the application common named pipe. | |
385 | */ | |
386 | /* TODO */ | |
387 | ||
388 | void __attribute__((constructor)) lttng_ust_comm_init(void) | |
389 | { | |
11ff9c7d | 390 | struct timespec constructor_timeout; |
cf12a773 | 391 | int timeout_mode; |
2691221a MD |
392 | int ret; |
393 | ||
394 | init_usterr(); | |
395 | ||
cf12a773 | 396 | timeout_mode = get_timeout(&constructor_timeout); |
11ff9c7d MD |
397 | |
398 | ret = sem_init(&constructor_wait, 0, 2); | |
399 | assert(!ret); | |
400 | ||
9eb62b9c | 401 | ret = setup_local_apps_socket(); |
2691221a | 402 | if (ret) { |
9eb62b9c | 403 | ERR("Error setting up to local apps socket"); |
2691221a | 404 | } |
11ff9c7d MD |
405 | |
406 | /* | |
407 | * Wait for the pthread cond to let us continue to main program | |
408 | * execution. Hold mutex across thread creation, so we start | |
409 | * waiting for the condition before the threads can signal its | |
410 | * completion. | |
411 | */ | |
412 | pthread_mutex_lock(<tng_ust_comm_mutex); | |
1ea11eab MD |
413 | ret = pthread_create(&global_apps.ust_listener, NULL, |
414 | ust_listener_thread, &global_apps); | |
1ea11eab MD |
415 | ret = pthread_create(&local_apps.ust_listener, NULL, |
416 | ust_listener_thread, &local_apps); | |
11ff9c7d | 417 | |
cf12a773 MD |
418 | switch (timeout_mode) { |
419 | case 1: /* timeout wait */ | |
420 | ret = sem_timedwait(&constructor_wait, &constructor_timeout); | |
421 | if (ret < 0 && errno == ETIMEDOUT) { | |
422 | ERR("Timed out waiting for ltt-sessiond"); | |
423 | } else { | |
424 | assert(!ret); | |
425 | } | |
426 | break; | |
427 | case 0: /* wait forever */ | |
428 | ret = sem_wait(&constructor_wait); | |
11ff9c7d | 429 | assert(!ret); |
cf12a773 MD |
430 | break; |
431 | case -1:/* no timeout */ | |
432 | break; | |
11ff9c7d MD |
433 | } |
434 | pthread_mutex_unlock(<tng_ust_comm_mutex); | |
2691221a MD |
435 | } |
436 | ||
437 | void __attribute__((destructor)) lttng_ust_comm_exit(void) | |
438 | { | |
439 | int ret; | |
440 | ||
9eb62b9c MD |
441 | /* |
442 | * Using pthread_cancel here because: | |
443 | * A) we don't want to hang application teardown. | |
444 | * B) the thread is not allocating any resource. | |
445 | */ | |
1ea11eab MD |
446 | |
447 | /* | |
448 | * Require the communication thread to quit. Synchronize with | |
449 | * mutexes to ensure it is not in a mutex critical section when | |
450 | * pthread_cancel is later called. | |
451 | */ | |
452 | pthread_mutex_lock(<tng_ust_comm_mutex); | |
453 | lttng_ust_comm_should_quit = 1; | |
454 | pthread_mutex_unlock(<tng_ust_comm_mutex); | |
455 | ||
456 | #if 0 | |
457 | ret = pthread_cancel(global_apps.ust_listener); | |
9eb62b9c MD |
458 | if (ret) { |
459 | ERR("Error cancelling global ust listener thread"); | |
2691221a | 460 | } |
1ea11eab | 461 | #endif //0 |
46050b1a MD |
462 | |
463 | cleanup_sock_info(&global_apps); | |
1ea11eab MD |
464 | |
465 | ret = pthread_cancel(local_apps.ust_listener); | |
9eb62b9c MD |
466 | if (ret) { |
467 | ERR("Error cancelling local ust listener thread"); | |
2691221a | 468 | } |
1ea11eab | 469 | |
46050b1a | 470 | cleanup_sock_info(&local_apps); |
1ea11eab | 471 | |
b35d179d | 472 | lttng_ust_abi_exit(); |
1ea11eab | 473 | ltt_events_exit(); |
2691221a | 474 | } |