2 * Copyright (C) 2011 EfficiOS Inc.
3 * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 * Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@efficios.com>
6 * SPDX-License-Identifier: GPL-2.0-only
13 #include <common/futex.h>
14 #include <common/macros.h>
15 #include <common/shm.h>
16 #include <common/utils.h>
20 #include "lttng-sessiond.h"
21 #include "testpoint.h"
22 #include "health-sessiond.h"
28 struct lttng_pipe
*quit_pipe
;
29 struct ust_cmd_queue
*ust_cmd_queue
;
32 int application_socket
;
36 * Creates the application socket.
38 static int create_application_socket(void)
43 /* Create the application unix socket */
44 apps_sock
= lttcomm_create_unix_sock(
45 the_config
.apps_unix_sock_path
.value
);
47 ERR("Create unix sock failed: %s",
48 the_config
.apps_unix_sock_path
.value
);
53 /* Set the cloexec flag */
54 ret
= utils_set_fd_cloexec(apps_sock
);
56 ERR("Unable to set CLOEXEC flag to the app Unix socket (fd: %d). "
57 "Continuing but note that the consumer daemon will have a "
58 "reference to this socket on exec()", apps_sock
);
61 /* File permission MUST be 666 */
62 ret
= chmod(the_config
.apps_unix_sock_path
.value
,
63 S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
| S_IROTH
|
66 PERROR("Set file permissions failed on %s",
67 the_config
.apps_unix_sock_path
.value
);
68 goto error_close_socket
;
71 DBG3("Session daemon application socket created (fd = %d) ", apps_sock
);
76 if (close(apps_sock
)) {
77 PERROR("Failed to close application socket in error path");
85 * Notify UST applications using the shm mmap futex.
87 static int notify_ust_apps(int active
, bool is_root
)
91 DBG("Notifying applications of session daemon state: %d", active
);
93 /* See shm.c for this call implying mmap, shm and futex calls */
94 wait_shm_mmap
= shm_ust_get_mmap(
95 the_config
.wait_shm_path
.value
, is_root
);
96 if (wait_shm_mmap
== NULL
) {
100 /* Wake waiting process */
101 futex_wait_update((int32_t *) wait_shm_mmap
, active
);
103 /* Apps notified successfully */
110 static void cleanup_application_registration_thread(void *data
)
112 struct thread_state
*thread_state
= data
;
118 lttng_pipe_destroy(thread_state
->quit_pipe
);
122 static void set_thread_status(struct thread_state
*thread_state
, bool running
)
124 DBG("Marking application registration thread's state as %s", running
? "running" : "error");
125 thread_state
->running
= running
;
126 sem_post(&thread_state
->ready
);
129 static bool wait_thread_status(struct thread_state
*thread_state
)
131 DBG("Waiting for application registration thread to be ready");
132 sem_wait(&thread_state
->ready
);
133 if (thread_state
->running
) {
134 DBG("Application registration thread is ready");
136 ERR("Initialization of application registration thread failed");
139 return thread_state
->running
;
142 static void thread_init_cleanup(void *data
)
144 struct thread_state
*thread_state
= data
;
146 set_thread_status(thread_state
, false);
150 * This thread manage application registration.
152 static void *thread_application_registration(void *data
)
154 int sock
= -1, i
, ret
, pollfd
, err
= -1;
155 uint32_t revents
, nb_fd
;
156 struct lttng_poll_event events
;
158 * Gets allocated in this thread, enqueued to a global queue, dequeued
159 * and freed in the manage apps thread.
161 struct ust_command
*ust_cmd
= NULL
;
162 const bool is_root
= (getuid() == 0);
163 struct thread_state
*thread_state
= data
;
164 const int application_socket
= thread_state
->application_socket
;
165 const int quit_pipe_read_fd
= lttng_pipe_get_readfd(
166 thread_state
->quit_pipe
);
168 DBG("[thread] Manage application registration started");
170 pthread_cleanup_push(thread_init_cleanup
, thread_state
);
171 health_register(the_health_sessiond
, HEALTH_SESSIOND_TYPE_APP_REG
);
173 ret
= lttcomm_listen_unix_sock(application_socket
);
179 * Pass 2 as size here for the thread quit pipe and apps_sock. Nothing
180 * more will be added to this poll set.
182 ret
= lttng_poll_create(&events
, 2, LTTNG_CLOEXEC
);
184 goto error_create_poll
;
187 /* Add the application registration socket */
188 ret
= lttng_poll_add(&events
, application_socket
, LPOLLIN
| LPOLLRDHUP
);
193 /* Add the application registration socket */
194 ret
= lttng_poll_add(&events
, quit_pipe_read_fd
, LPOLLIN
| LPOLLRDHUP
);
199 set_thread_status(thread_state
, true);
200 pthread_cleanup_pop(0);
202 if (testpoint(sessiond_thread_registration_apps
)) {
207 DBG("Accepting application registration");
209 /* Inifinite blocking call, waiting for transmission */
212 ret
= lttng_poll_wait(&events
, -1);
216 * Restart interrupted system call.
218 if (errno
== EINTR
) {
226 for (i
= 0; i
< nb_fd
; i
++) {
227 health_code_update();
229 /* Fetch once the poll data */
230 revents
= LTTNG_POLL_GETEV(&events
, i
);
231 pollfd
= LTTNG_POLL_GETFD(&events
, i
);
233 /* Thread quit pipe has been closed. Killing thread. */
234 if (pollfd
== quit_pipe_read_fd
) {
238 /* Event on the registration socket */
239 if (revents
& LPOLLIN
) {
240 sock
= lttcomm_accept_unix_sock(application_socket
);
246 * Set socket timeout for both receiving and ending.
247 * app_socket_timeout is in seconds, whereas
248 * lttcomm_setsockopt_rcv_timeout and
249 * lttcomm_setsockopt_snd_timeout expect msec as
252 if (the_config
.app_socket_timeout
>= 0) {
253 (void) lttcomm_setsockopt_rcv_timeout(sock
,
254 the_config
.app_socket_timeout
* 1000);
255 (void) lttcomm_setsockopt_snd_timeout(sock
,
256 the_config
.app_socket_timeout
* 1000);
260 * Set the CLOEXEC flag. Return code is useless because
261 * either way, the show must go on.
263 (void) utils_set_fd_cloexec(sock
);
265 /* Create UST registration command for enqueuing */
266 ust_cmd
= zmalloc(sizeof(struct ust_command
));
267 if (ust_cmd
== NULL
) {
268 PERROR("ust command zmalloc");
278 * Using message-based transmissions to ensure we don't
279 * have to deal with partially received messages.
281 ret
= lttng_fd_get(LTTNG_FD_APPS
, 1);
283 ERR("Exhausted file descriptors allowed for applications.");
293 health_code_update();
294 ret
= ust_app_recv_registration(sock
, &ust_cmd
->reg_msg
);
297 /* Close socket of the application. */
302 lttng_fd_put(LTTNG_FD_APPS
, 1);
306 health_code_update();
308 ust_cmd
->sock
= sock
;
311 DBG("UST registration received with pid:%d ppid:%d uid:%d"
312 " gid:%d sock:%d name:%s (version %d.%d)",
313 ust_cmd
->reg_msg
.pid
, ust_cmd
->reg_msg
.ppid
,
314 ust_cmd
->reg_msg
.uid
, ust_cmd
->reg_msg
.gid
,
315 ust_cmd
->sock
, ust_cmd
->reg_msg
.name
,
316 ust_cmd
->reg_msg
.major
, ust_cmd
->reg_msg
.minor
);
319 * Lock free enqueue the registration request. The red pill
320 * has been taken! This apps will be part of the *system*.
322 cds_wfcq_enqueue(&thread_state
->ust_cmd_queue
->head
,
323 &thread_state
->ust_cmd_queue
->tail
,
327 * Wake the registration queue futex. Implicit memory
328 * barrier with the exchange in cds_wfcq_enqueue.
330 futex_nto1_wake(&thread_state
->ust_cmd_queue
->futex
);
331 } else if (revents
& (LPOLLERR
| LPOLLHUP
| LPOLLRDHUP
)) {
332 ERR("Register apps socket poll error");
335 ERR("Unexpected poll events %u for sock %d", revents
, pollfd
);
344 /* Notify that the registration thread is gone */
345 notify_ust_apps(0, is_root
);
347 ret
= close(application_socket
);
349 PERROR("Failed to close application registration socket");
354 PERROR("Failed to close application socket");
356 lttng_fd_put(LTTNG_FD_APPS
, 1);
358 unlink(the_config
.apps_unix_sock_path
.value
);
361 lttng_poll_clean(&events
);
364 DBG("UST Registration thread cleanup complete");
367 ERR("Health error occurred in %s", __func__
);
369 health_unregister(the_health_sessiond
);
373 static bool shutdown_application_registration_thread(void *data
)
375 struct thread_state
*thread_state
= data
;
376 const int write_fd
= lttng_pipe_get_writefd(thread_state
->quit_pipe
);
378 return notify_thread_pipe(write_fd
) == 1;
381 struct lttng_thread
*launch_application_registration_thread(
382 struct ust_cmd_queue
*cmd_queue
)
385 struct lttng_pipe
*quit_pipe
;
386 struct thread_state
*thread_state
= NULL
;
387 struct lttng_thread
*thread
= NULL
;
388 const bool is_root
= (getuid() == 0);
389 int application_socket
= -1;
391 thread_state
= zmalloc(sizeof(*thread_state
));
395 quit_pipe
= lttng_pipe_open(FD_CLOEXEC
);
399 thread_state
->quit_pipe
= quit_pipe
;
400 thread_state
->ust_cmd_queue
= cmd_queue
;
401 application_socket
= create_application_socket();
402 if (application_socket
< 0) {
405 thread_state
->application_socket
= application_socket
;
406 sem_init(&thread_state
->ready
, 0, 0);
408 thread
= lttng_thread_create("UST application registration",
409 thread_application_registration
,
410 shutdown_application_registration_thread
,
411 cleanup_application_registration_thread
,
417 * The application registration thread now owns the application socket
418 * and the global thread state. The thread state is used to wait for
419 * the thread's status, but its ownership now belongs to the thread.
421 application_socket
= -1;
422 if (!wait_thread_status(thread_state
)) {
427 /* Notify all applications to register. */
428 ret
= notify_ust_apps(1, is_root
);
430 ERR("Failed to notify applications or create the wait shared memory.\n"
431 "Execution continues but there might be problems for already\n"
432 "running applications that wishes to register.");
437 lttng_thread_put(thread
);
438 cleanup_application_registration_thread(thread_state
);
439 if (application_socket
>= 0) {
440 if (close(application_socket
)) {
441 PERROR("Failed to close application registration socket");