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)
42 const mode_t old_umask
= umask(0);
44 /* Create the application unix socket */
45 apps_sock
= lttcomm_create_unix_sock(
46 the_config
.apps_unix_sock_path
.value
);
48 ERR("Create unix sock failed: %s",
49 the_config
.apps_unix_sock_path
.value
);
54 /* Set the cloexec flag */
55 ret
= utils_set_fd_cloexec(apps_sock
);
57 ERR("Unable to set CLOEXEC flag to the app Unix socket (fd: %d). "
58 "Continuing but note that the consumer daemon will have a "
59 "reference to this socket on exec()", apps_sock
);
62 /* File permission MUST be 666 */
63 ret
= chmod(the_config
.apps_unix_sock_path
.value
,
64 S_IRUSR
| S_IWUSR
| S_IRGRP
| S_IWGRP
| S_IROTH
|
67 PERROR("Set file permissions failed on %s",
68 the_config
.apps_unix_sock_path
.value
);
69 goto error_close_socket
;
72 DBG3("Session daemon application socket created (fd = %d) ", apps_sock
);
78 if (close(apps_sock
)) {
79 PERROR("Failed to close application socket in error path");
87 * Notify UST applications using the shm mmap futex.
89 static int notify_ust_apps(int active
, bool is_root
)
93 DBG("Notifying applications of session daemon state: %d", active
);
95 /* See shm.c for this call implying mmap, shm and futex calls */
96 wait_shm_mmap
= shm_ust_get_mmap(
97 the_config
.wait_shm_path
.value
, is_root
);
98 if (wait_shm_mmap
== NULL
) {
102 /* Wake waiting process */
103 futex_wait_update((int32_t *) wait_shm_mmap
, active
);
105 /* Apps notified successfully */
112 static void cleanup_application_registration_thread(void *data
)
114 struct thread_state
*thread_state
= (struct thread_state
*) data
;
120 lttng_pipe_destroy(thread_state
->quit_pipe
);
124 static void set_thread_status(struct thread_state
*thread_state
, bool running
)
126 DBG("Marking application registration thread's state as %s", running
? "running" : "error");
127 thread_state
->running
= running
;
128 sem_post(&thread_state
->ready
);
131 static bool wait_thread_status(struct thread_state
*thread_state
)
133 DBG("Waiting for application registration thread to be ready");
134 sem_wait(&thread_state
->ready
);
135 if (thread_state
->running
) {
136 DBG("Application registration thread is ready");
138 ERR("Initialization of application registration thread failed");
141 return thread_state
->running
;
144 static void thread_init_cleanup(void *data
)
146 struct thread_state
*thread_state
= (struct thread_state
*) data
;
148 set_thread_status(thread_state
, false);
152 * This thread manage application registration.
154 static void *thread_application_registration(void *data
)
156 int sock
= -1, i
, ret
, pollfd
, err
= -1;
157 uint32_t revents
, nb_fd
;
158 struct lttng_poll_event events
;
160 * Gets allocated in this thread, enqueued to a global queue, dequeued
161 * and freed in the manage apps thread.
163 struct ust_command
*ust_cmd
= NULL
;
164 const bool is_root
= (getuid() == 0);
165 struct thread_state
*thread_state
= (struct thread_state
*) data
;
166 const int application_socket
= thread_state
->application_socket
;
167 const int quit_pipe_read_fd
= lttng_pipe_get_readfd(
168 thread_state
->quit_pipe
);
170 DBG("[thread] Manage application registration started");
172 pthread_cleanup_push(thread_init_cleanup
, thread_state
);
173 health_register(the_health_sessiond
, HEALTH_SESSIOND_TYPE_APP_REG
);
175 ret
= lttcomm_listen_unix_sock(application_socket
);
181 * Pass 2 as size here for the thread quit pipe and apps_sock. Nothing
182 * more will be added to this poll set.
184 ret
= lttng_poll_create(&events
, 2, LTTNG_CLOEXEC
);
186 goto error_create_poll
;
189 /* Add the application registration socket */
190 ret
= lttng_poll_add(&events
, application_socket
, LPOLLIN
| LPOLLRDHUP
);
195 /* Add the application registration socket */
196 ret
= lttng_poll_add(&events
, quit_pipe_read_fd
, LPOLLIN
| LPOLLRDHUP
);
201 set_thread_status(thread_state
, true);
202 pthread_cleanup_pop(0);
204 if (testpoint(sessiond_thread_registration_apps
)) {
209 DBG("Accepting application registration");
211 /* Inifinite blocking call, waiting for transmission */
214 ret
= lttng_poll_wait(&events
, -1);
218 * Restart interrupted system call.
220 if (errno
== EINTR
) {
228 for (i
= 0; i
< nb_fd
; i
++) {
229 health_code_update();
231 /* Fetch once the poll data */
232 revents
= LTTNG_POLL_GETEV(&events
, i
);
233 pollfd
= LTTNG_POLL_GETFD(&events
, i
);
235 /* Thread quit pipe has been closed. Killing thread. */
236 if (pollfd
== quit_pipe_read_fd
) {
240 /* Event on the registration socket */
241 if (revents
& LPOLLIN
) {
242 sock
= lttcomm_accept_unix_sock(application_socket
);
248 * Set socket timeout for both receiving and ending.
249 * app_socket_timeout is in seconds, whereas
250 * lttcomm_setsockopt_rcv_timeout and
251 * lttcomm_setsockopt_snd_timeout expect msec as
254 if (the_config
.app_socket_timeout
>= 0) {
255 (void) lttcomm_setsockopt_rcv_timeout(sock
,
256 the_config
.app_socket_timeout
* 1000);
257 (void) lttcomm_setsockopt_snd_timeout(sock
,
258 the_config
.app_socket_timeout
* 1000);
262 * Set the CLOEXEC flag. Return code is useless because
263 * either way, the show must go on.
265 (void) utils_set_fd_cloexec(sock
);
267 /* Create UST registration command for enqueuing */
268 ust_cmd
= (ust_command
*) zmalloc(sizeof(struct ust_command
));
269 if (ust_cmd
== NULL
) {
270 PERROR("ust command zmalloc");
280 * Using message-based transmissions to ensure we don't
281 * have to deal with partially received messages.
283 ret
= lttng_fd_get(LTTNG_FD_APPS
, 1);
285 ERR("Exhausted file descriptors allowed for applications.");
295 health_code_update();
296 ret
= ust_app_recv_registration(sock
, &ust_cmd
->reg_msg
);
299 /* Close socket of the application. */
304 lttng_fd_put(LTTNG_FD_APPS
, 1);
308 health_code_update();
310 ust_cmd
->sock
= sock
;
313 DBG("UST registration received with pid:%d ppid:%d uid:%d"
314 " gid:%d sock:%d name:%s (version %d.%d)",
315 ust_cmd
->reg_msg
.pid
, ust_cmd
->reg_msg
.ppid
,
316 ust_cmd
->reg_msg
.uid
, ust_cmd
->reg_msg
.gid
,
317 ust_cmd
->sock
, ust_cmd
->reg_msg
.name
,
318 ust_cmd
->reg_msg
.major
, ust_cmd
->reg_msg
.minor
);
321 * Lock free enqueue the registration request. The red pill
322 * has been taken! This apps will be part of the *system*.
324 cds_wfcq_head_ptr_t head
;
325 head
.h
= &thread_state
->ust_cmd_queue
->head
;
326 cds_wfcq_enqueue(head
,
327 &thread_state
->ust_cmd_queue
->tail
,
331 * Wake the registration queue futex. Implicit memory
332 * barrier with the exchange in cds_wfcq_enqueue.
334 futex_nto1_wake(&thread_state
->ust_cmd_queue
->futex
);
335 } else if (revents
& (LPOLLERR
| LPOLLHUP
| LPOLLRDHUP
)) {
336 ERR("Register apps socket poll error");
339 ERR("Unexpected poll events %u for sock %d", revents
, pollfd
);
348 /* Notify that the registration thread is gone */
349 notify_ust_apps(0, is_root
);
351 ret
= close(application_socket
);
353 PERROR("Failed to close application registration socket");
358 PERROR("Failed to close application socket");
360 lttng_fd_put(LTTNG_FD_APPS
, 1);
362 unlink(the_config
.apps_unix_sock_path
.value
);
365 lttng_poll_clean(&events
);
368 DBG("UST Registration thread cleanup complete");
371 ERR("Health error occurred in %s", __func__
);
373 health_unregister(the_health_sessiond
);
377 static bool shutdown_application_registration_thread(void *data
)
379 struct thread_state
*thread_state
= (struct thread_state
*) data
;
380 const int write_fd
= lttng_pipe_get_writefd(thread_state
->quit_pipe
);
382 return notify_thread_pipe(write_fd
) == 1;
385 struct lttng_thread
*launch_application_registration_thread(
386 struct ust_cmd_queue
*cmd_queue
)
389 struct lttng_pipe
*quit_pipe
;
390 struct thread_state
*thread_state
= NULL
;
391 struct lttng_thread
*thread
= NULL
;
392 const bool is_root
= (getuid() == 0);
393 int application_socket
= -1;
395 thread_state
= (struct thread_state
*) zmalloc(sizeof(*thread_state
));
399 quit_pipe
= lttng_pipe_open(FD_CLOEXEC
);
403 thread_state
->quit_pipe
= quit_pipe
;
404 thread_state
->ust_cmd_queue
= cmd_queue
;
405 application_socket
= create_application_socket();
406 if (application_socket
< 0) {
409 thread_state
->application_socket
= application_socket
;
410 sem_init(&thread_state
->ready
, 0, 0);
412 thread
= lttng_thread_create("UST application registration",
413 thread_application_registration
,
414 shutdown_application_registration_thread
,
415 cleanup_application_registration_thread
,
421 * The application registration thread now owns the application socket
422 * and the global thread state. The thread state is used to wait for
423 * the thread's status, but its ownership now belongs to the thread.
425 application_socket
= -1;
426 if (!wait_thread_status(thread_state
)) {
431 /* Notify all applications to register. */
432 ret
= notify_ust_apps(1, is_root
);
434 ERR("Failed to notify applications or create the wait shared memory.\n"
435 "Execution continues but there might be problems for already\n"
436 "running applications that wishes to register.");
441 lttng_thread_put(thread
);
442 cleanup_application_registration_thread(thread_state
);
443 if (application_socket
>= 0) {
444 if (close(application_socket
)) {
445 PERROR("Failed to close application registration socket");