Commit | Line | Data |
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22b80785 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 | ||
37 | struct thread_notifiers { | |
38 | struct lttng_pipe *quit_pipe; | |
39 | struct ust_cmd_queue *ust_cmd_queue; | |
40 | }; | |
41 | ||
42 | /* | |
43 | * Creates the application socket. | |
44 | */ | |
45 | static int create_application_socket(void) | |
46 | { | |
47 | int ret = 0; | |
48 | int apps_sock; | |
49 | const mode_t old_umask = umask(0); | |
50 | ||
51 | /* Create the application unix socket */ | |
52 | apps_sock = lttcomm_create_unix_sock(config.apps_unix_sock_path.value); | |
53 | if (apps_sock < 0) { | |
54 | ERR("Create unix sock failed: %s", config.apps_unix_sock_path.value); | |
55 | ret = -1; | |
56 | goto end; | |
57 | } | |
58 | ||
59 | /* Set the cloexec flag */ | |
60 | ret = utils_set_fd_cloexec(apps_sock); | |
61 | if (ret < 0) { | |
62 | ERR("Unable to set CLOEXEC flag to the app Unix socket (fd: %d). " | |
63 | "Continuing but note that the consumer daemon will have a " | |
64 | "reference to this socket on exec()", apps_sock); | |
65 | } | |
66 | ||
67 | /* File permission MUST be 666 */ | |
68 | ret = chmod(config.apps_unix_sock_path.value, | |
69 | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH); | |
70 | if (ret < 0) { | |
71 | PERROR("Set file permissions failed on %s", | |
72 | config.apps_unix_sock_path.value); | |
73 | goto end; | |
74 | } | |
75 | ||
76 | DBG3("Session daemon application socket created (fd = %d) ", apps_sock); | |
77 | ret = apps_sock; | |
78 | end: | |
79 | umask(old_umask); | |
80 | return ret; | |
81 | } | |
82 | ||
83 | /* | |
84 | * Notify UST applications using the shm mmap futex. | |
85 | */ | |
86 | static int notify_ust_apps(int active, bool is_root) | |
87 | { | |
88 | char *wait_shm_mmap; | |
89 | ||
90 | DBG("Notifying applications of session daemon state: %d", active); | |
91 | ||
92 | /* See shm.c for this call implying mmap, shm and futex calls */ | |
93 | wait_shm_mmap = shm_ust_get_mmap(config.wait_shm_path.value, is_root); | |
94 | if (wait_shm_mmap == NULL) { | |
95 | goto error; | |
96 | } | |
97 | ||
98 | /* Wake waiting process */ | |
99 | futex_wait_update((int32_t *) wait_shm_mmap, active); | |
100 | ||
101 | /* Apps notified successfully */ | |
102 | return 0; | |
103 | ||
104 | error: | |
105 | return -1; | |
106 | } | |
107 | ||
108 | static void cleanup_application_registration_thread(void *data) | |
109 | { | |
110 | struct thread_notifiers *notifiers = data; | |
111 | ||
112 | lttng_pipe_destroy(notifiers->quit_pipe); | |
113 | free(notifiers); | |
114 | } | |
115 | ||
116 | /* | |
117 | * This thread manage application registration. | |
118 | */ | |
119 | static void *thread_application_registration(void *data) | |
120 | { | |
121 | int sock = -1, i, ret, pollfd, err = -1; | |
122 | int apps_sock = -1; | |
123 | uint32_t revents, nb_fd; | |
124 | struct lttng_poll_event events; | |
125 | /* | |
126 | * Gets allocated in this thread, enqueued to a global queue, dequeued | |
127 | * and freed in the manage apps thread. | |
128 | */ | |
129 | struct ust_command *ust_cmd = NULL; | |
130 | const bool is_root = (getuid() == 0); | |
131 | struct thread_notifiers *notifiers = data; | |
132 | const int quit_pipe_read_fd = lttng_pipe_get_readfd( | |
133 | notifiers->quit_pipe); | |
134 | ||
135 | DBG("[thread] Manage application registration started"); | |
136 | ||
137 | health_register(health_sessiond, HEALTH_SESSIOND_TYPE_APP_REG); | |
138 | ||
139 | if (testpoint(sessiond_thread_registration_apps)) { | |
140 | goto error_testpoint; | |
141 | } | |
142 | ||
143 | apps_sock = create_application_socket(); | |
144 | if (apps_sock < 0) { | |
145 | goto error_listen; | |
146 | } | |
147 | ||
148 | ret = lttcomm_listen_unix_sock(apps_sock); | |
149 | if (ret < 0) { | |
150 | goto error_listen; | |
151 | } | |
152 | ||
153 | /* | |
154 | * Pass 2 as size here for the thread quit pipe and apps_sock. Nothing | |
155 | * more will be added to this poll set. | |
156 | */ | |
157 | ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC); | |
158 | if (ret < 0) { | |
159 | goto error_create_poll; | |
160 | } | |
161 | ||
162 | /* Add the application registration socket */ | |
163 | ret = lttng_poll_add(&events, apps_sock, LPOLLIN | LPOLLRDHUP); | |
164 | if (ret < 0) { | |
165 | goto error_poll_add; | |
166 | } | |
167 | ||
168 | /* Add the application registration socket */ | |
169 | ret = lttng_poll_add(&events, quit_pipe_read_fd, LPOLLIN | LPOLLRDHUP); | |
170 | if (ret < 0) { | |
171 | goto error_poll_add; | |
172 | } | |
173 | ||
174 | /* Notify all applications to register */ | |
175 | ret = notify_ust_apps(1, is_root); | |
176 | if (ret < 0) { | |
177 | ERR("Failed to notify applications or create the wait shared memory.\n" | |
178 | "Execution continues but there might be problem for already\n" | |
179 | "running applications that wishes to register."); | |
180 | } | |
181 | ||
182 | while (1) { | |
183 | DBG("Accepting application registration"); | |
184 | ||
185 | /* Inifinite blocking call, waiting for transmission */ | |
186 | restart: | |
187 | health_poll_entry(); | |
188 | ret = lttng_poll_wait(&events, -1); | |
189 | health_poll_exit(); | |
190 | if (ret < 0) { | |
191 | /* | |
192 | * Restart interrupted system call. | |
193 | */ | |
194 | if (errno == EINTR) { | |
195 | goto restart; | |
196 | } | |
197 | goto error; | |
198 | } | |
199 | ||
200 | nb_fd = ret; | |
201 | ||
202 | for (i = 0; i < nb_fd; i++) { | |
203 | health_code_update(); | |
204 | ||
205 | /* Fetch once the poll data */ | |
206 | revents = LTTNG_POLL_GETEV(&events, i); | |
207 | pollfd = LTTNG_POLL_GETFD(&events, i); | |
208 | ||
209 | if (!revents) { | |
210 | /* No activity for this FD (poll implementation). */ | |
211 | continue; | |
212 | } | |
213 | ||
214 | /* Thread quit pipe has been closed. Killing thread. */ | |
215 | if (pollfd == quit_pipe_read_fd) { | |
216 | err = 0; | |
217 | goto exit; | |
218 | } else { | |
219 | /* Event on the registration socket */ | |
220 | if (revents & LPOLLIN) { | |
221 | sock = lttcomm_accept_unix_sock(apps_sock); | |
222 | if (sock < 0) { | |
223 | goto error; | |
224 | } | |
225 | ||
226 | /* | |
227 | * Set socket timeout for both receiving and ending. | |
228 | * app_socket_timeout is in seconds, whereas | |
229 | * lttcomm_setsockopt_rcv_timeout and | |
230 | * lttcomm_setsockopt_snd_timeout expect msec as | |
231 | * parameter. | |
232 | */ | |
233 | if (config.app_socket_timeout >= 0) { | |
234 | (void) lttcomm_setsockopt_rcv_timeout(sock, | |
235 | config.app_socket_timeout * 1000); | |
236 | (void) lttcomm_setsockopt_snd_timeout(sock, | |
237 | config.app_socket_timeout * 1000); | |
238 | } | |
239 | ||
240 | /* | |
241 | * Set the CLOEXEC flag. Return code is useless because | |
242 | * either way, the show must go on. | |
243 | */ | |
244 | (void) utils_set_fd_cloexec(sock); | |
245 | ||
246 | /* Create UST registration command for enqueuing */ | |
247 | ust_cmd = zmalloc(sizeof(struct ust_command)); | |
248 | if (ust_cmd == NULL) { | |
249 | PERROR("ust command zmalloc"); | |
250 | ret = close(sock); | |
251 | if (ret) { | |
252 | PERROR("close"); | |
253 | } | |
254 | goto error; | |
255 | } | |
256 | ||
257 | /* | |
258 | * Using message-based transmissions to ensure we don't | |
259 | * have to deal with partially received messages. | |
260 | */ | |
261 | ret = lttng_fd_get(LTTNG_FD_APPS, 1); | |
262 | if (ret < 0) { | |
263 | ERR("Exhausted file descriptors allowed for applications."); | |
264 | free(ust_cmd); | |
265 | ret = close(sock); | |
266 | if (ret) { | |
267 | PERROR("close"); | |
268 | } | |
269 | sock = -1; | |
270 | continue; | |
271 | } | |
272 | ||
273 | health_code_update(); | |
274 | ret = ust_app_recv_registration(sock, &ust_cmd->reg_msg); | |
275 | if (ret < 0) { | |
276 | free(ust_cmd); | |
277 | /* Close socket of the application. */ | |
278 | ret = close(sock); | |
279 | if (ret) { | |
280 | PERROR("close"); | |
281 | } | |
282 | lttng_fd_put(LTTNG_FD_APPS, 1); | |
283 | sock = -1; | |
284 | continue; | |
285 | } | |
286 | health_code_update(); | |
287 | ||
288 | ust_cmd->sock = sock; | |
289 | sock = -1; | |
290 | ||
291 | DBG("UST registration received with pid:%d ppid:%d uid:%d" | |
292 | " gid:%d sock:%d name:%s (version %d.%d)", | |
293 | ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid, | |
294 | ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid, | |
295 | ust_cmd->sock, ust_cmd->reg_msg.name, | |
296 | ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor); | |
297 | ||
298 | /* | |
299 | * Lock free enqueue the registration request. The red pill | |
300 | * has been taken! This apps will be part of the *system*. | |
301 | */ | |
302 | cds_wfcq_enqueue(¬ifiers->ust_cmd_queue->head, | |
303 | ¬ifiers->ust_cmd_queue->tail, | |
304 | &ust_cmd->node); | |
305 | ||
306 | /* | |
307 | * Wake the registration queue futex. Implicit memory | |
308 | * barrier with the exchange in cds_wfcq_enqueue. | |
309 | */ | |
310 | futex_nto1_wake(¬ifiers->ust_cmd_queue->futex); | |
311 | } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) { | |
312 | ERR("Register apps socket poll error"); | |
313 | goto error; | |
314 | } else { | |
315 | ERR("Unexpected poll events %u for sock %d", revents, pollfd); | |
316 | goto error; | |
317 | } | |
318 | } | |
319 | } | |
320 | } | |
321 | ||
322 | exit: | |
323 | error: | |
324 | /* Notify that the registration thread is gone */ | |
325 | notify_ust_apps(0, is_root); | |
326 | ||
327 | if (apps_sock >= 0) { | |
328 | ret = close(apps_sock); | |
329 | if (ret) { | |
330 | PERROR("close"); | |
331 | } | |
332 | } | |
333 | if (sock >= 0) { | |
334 | ret = close(sock); | |
335 | if (ret) { | |
336 | PERROR("close"); | |
337 | } | |
338 | lttng_fd_put(LTTNG_FD_APPS, 1); | |
339 | } | |
340 | unlink(config.apps_unix_sock_path.value); | |
341 | ||
342 | error_poll_add: | |
343 | lttng_poll_clean(&events); | |
344 | error_listen: | |
345 | error_create_poll: | |
346 | error_testpoint: | |
347 | DBG("UST Registration thread cleanup complete"); | |
348 | if (err) { | |
349 | health_error(); | |
350 | ERR("Health error occurred in %s", __func__); | |
351 | } | |
352 | health_unregister(health_sessiond); | |
353 | return NULL; | |
354 | } | |
355 | ||
356 | static bool shutdown_application_registration_thread(void *data) | |
357 | { | |
358 | struct thread_notifiers *notifiers = data; | |
359 | const int write_fd = lttng_pipe_get_writefd(notifiers->quit_pipe); | |
360 | ||
361 | return notify_thread_pipe(write_fd) == 1; | |
362 | } | |
363 | ||
143745a6 | 364 | struct lttng_thread *launch_application_registration_thread( |
22b80785 JG |
365 | struct ust_cmd_queue *cmd_queue) |
366 | { | |
367 | struct lttng_pipe *quit_pipe; | |
368 | struct thread_notifiers *notifiers = NULL; | |
369 | struct lttng_thread *thread; | |
370 | ||
371 | quit_pipe = lttng_pipe_open(FD_CLOEXEC); | |
372 | if (!quit_pipe) { | |
373 | goto error; | |
374 | } | |
375 | ||
376 | notifiers = zmalloc(sizeof(*notifiers)); | |
377 | if (!notifiers) { | |
378 | goto error; | |
379 | } | |
380 | notifiers->quit_pipe = quit_pipe; | |
381 | notifiers->ust_cmd_queue = cmd_queue; | |
382 | ||
383 | thread = lttng_thread_create("UST application registration", | |
384 | thread_application_registration, | |
385 | shutdown_application_registration_thread, | |
386 | cleanup_application_registration_thread, | |
387 | notifiers); | |
388 | if (!thread) { | |
389 | goto error; | |
390 | } | |
143745a6 | 391 | return thread; |
22b80785 JG |
392 | error: |
393 | cleanup_application_registration_thread(notifiers); | |
143745a6 | 394 | return NULL; |
22b80785 | 395 | } |